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Fulltext Phenotype microarrays reveal metabolic dysregulations of neurospheres derived from embryonic Ts1Cje mouse model of Down syndrome

Seth EA, Lee HC, Yusof HHBM, Nordin N, Cheah YK, Ho ETW, et al.

PLoS One, 2020;15(7):e0236826.
PMID: 32730314 DOI: 10.1371/journal.pone.0236826

Down syndrome (DS), is the most common cause of intellectual disability, and is characterized by defective neurogenesis during perinatal development. To identify metabolic aberrations in early neurogenesis, we profiled neurospheres derived from the embryonic brain of Ts1Cje, a mouse model of Down syndrome. High-throughput phenotypic microarray revealed a significant decrease in utilisation of 17 out of 367 substrates and significantly higher utilisation of 6 substrates in the Ts1Cje neurospheres compared to controls. Specifically, Ts1Cje neurospheres were less efficient in the utilisation of glucose-6-phosphate suggesting a dysregulation in the energy-producing pathway. T Cje neurospheres were significantly smaller in diameter than the controls. Subsequent preliminary study on supplementation with 6-phosphogluconic acid, an intermediate of glucose-6-phosphate metabolism, was able to rescue the Ts1Cje neurosphere size. This study confirmed the perturbed pentose phosphate pathway, contributing to defects observed in Ts1Cje neurospheres. We show for the first time that this comprehensive energetic assay platform facilitates the metabolic characterisation of Ts1Cje cells and confirmed their distinguishable metabolic profiles compared to the controls.

Matched MeSH terms: Brain/embryology
Fulltext Synthesis, Characterization, and Toxicity Assessment of Pluronic F127-Functionalized Graphene Oxide on the Embryonic Development of Zebrafish (Danio rerio)

Shamsi S, Alagan AA, Sarchio SNE, Md Yasin F

Int J Nanomedicine, 2020;15:8311-8329.
PMID: 33149578 DOI: 10.2147/IJN.S271159

Background: In the current literature, there are ongoing debates on the toxicity of graphene oxide (GO) that demonstrate contradictory findings regarding its toxicity profile. As a potential drug carrier, these findings are very concerning due to the safety concerns in humans, as well as the dramatic rise of GO being excreted into the environment. Therefore, there is an imperative need to mitigate the potential toxicity of GO to allow for a safer application in the future.
Purpose: The present study aims to address this issue by functionalizing GO with Pluronic F127 (PF) as a means to mitigate toxicity and resolve the biocompatibility of GO. Although results from previous studies generally indicated that Pluronic functionalized GO exhibits relatively low toxicity to living organisms, reports that emphasize on its toxicity, particularly during embryonic developmental stage, are still scarce.
Methods: In the present study, two different sizes of native GO samples, GO and NanoGO, as well as PF-functionalized GO, GO-PF and NanoGO-PF, were prepared and characterized using DLS, UV-Vis, Raman spectroscopy, FTIR, and FESEM analyses. Toxicological assessment of all GO samples (0-100 µg/mL) on zebrafish embryonic developmental stages (survival, hatching and heart rates, and morphological changes) was recorded daily for up to 96 hours post-fertilization (hpf).
Results: The toxicity effects of each GO sample were observed to be higher at increasing concentrations and upon prolonged exposure. NanoGO demonstrated lower toxicity effects compared to GO. GO-PF and NanoGO-PF were also found to have lower toxicity effects compared to native GO samples. GO-PF showed the lowest toxicity response on zebrafish embryo.
Conclusion: These findings highlight that toxicity is dependent on the concentration, size, and exposure period of GO. Functionalization of GO with PF through surface coating could potentially mitigate the toxicity effects of GO in embryonic developmental stages, but further investigation is warranted for broader future applications.

Matched MeSH terms: Zebrafish/embryology*
Cryopreservation of Citrus madurensis zygotic embryonic axes by vitrification: importance of pregrowth and preculture conditions

Cho EG, Hor YL, Kim HH, Rao VR, Engelmann F

Cryo Letters, 2001 Nov-Dec;22(6):391-6.
PMID: 11788881

The role of pregrowth and preculture treatments in terms of both medium composition and exposure duration on survival of embryonic axes of Citrus madurensis after cryopreservation using the vitrification procedure was investigated. The optimal pregrowth treatment for excised embryonic axes was a 3-day treatment with 0.1M sucrose. Preculture was also essential in increasing survival after cryopreservation. Among the various media and treatment durations evaluated, a 24h-preculture of embryonic axes on medium with 0.3M sucrose and 0.5M glycerol was found to be optimal. Using these pregrowth and preculture conditions followed by treatment at 25 degrees C for 20 min each with a loading solution (0.4M sucrose + 2.0M glycerol) and then the PVS2 vitrification solution, direct immersion in liquid nitrogen, rapid rewarming, unloading in a 1.2M sucrose solution for 20 min and transfer of embryonic axes on recovery medium, 82.5% survival and regrowth without intermediary callus formation were obtained with C. madurensis embryonic axes.

Matched MeSH terms: Citrus/embryology*
Fulltext Meconium peritonitis: prenatal diagnosis and postnatal management--a case report

Ramesh JC, Chow TWP, Yik YI, Ramanujam TM

Med J Malaysia, 1999 Dec;54(4):528-30.
PMID: 11072477

The management of a case of antenatally diagnosed meconium peritonitis (MP) due to intrauterine intestinal perforation secondary to bowel atresia is reported. The literature is reviewed with reference to the significance and outcome of antenatally diagnosed MP.

Matched MeSH terms: Intestinal Atresia/embryology
Cryopreservation of Citrus madurensis embryonic axes encapsulation-dehydration

Cho EG, Hor YL, Kim HH, Rao VR, Engelmann F

Cryo Letters, 2002 Sep-Oct;23(5):325-32.
PMID: 12447492

In this paper, we demonstrate that C. madurensis embryonic axes can withstand cryopreservation using the encapsulation-dehydration technique. Up to 57.5 % survival was achieved using a standard encapsulation-dehydration protocol, which included pregrowth of encapsulated axes for 16 h in medium containing 0.8 M sucrose + 1 M glycerol, desiccation of beads to around 30 % moisture content (fresh weight basis) followed by rapid freezing. A slightly higher survival percentage (65 %) was obtained using a modified encapsulation-dehydration protocol, which included pretreatment of axes with 2 M glycerol + 0.6 M sucrose for 1 h, concomitantly with their encapsulation in 3 % calcium alginate beads, followed by desiccation of the beads to around 30 % moisture content.

Matched MeSH terms: Citrus/embryology*
Cryopreservation of Citrus madurensis embryonic axes by vitrification: importance of loading and treatment with vitrification solution

Cho EG, Hor YL, Kim HH, Rao VR, Engelmann F

Cryo Letters, 2002 Sep-Oct;23(5):317-24.
PMID: 12447491

This paper investigates the importance of loading and treatment with a vitrification solution on the survival of Citrus madurensis embryonic axes cryopreserved using a vitrification protocol. Among the seven different loading solutions tested, the solution containing 2 M glycerol + 0.4 M sucrose was the most efficient. Of the six vitrification solutions tested, the PVS2 vitrification solution, applied for 20 min at 25 degree C or for 60 min at 0 degree C, ensured the highest survival. A three-step vitrification protocol, involving the treatment of embryonic axes at 0 degree C with half strength PVS2 solution for 20 min then with full strength PVS2 for an additional 40 min was more efficient than a two-step protocol that involved treatment of axes directly with full strength PVS2 solution for 60 min. After rapid immersion in liquid nitrogen, rapid rewarming, unloading in a 1.2 M sucrose solution for 20 min, culture on solid medium with 0.3 M sucrose for 1 day and growth recovery for 4 weeks on standard medium, survival of C. madurensis embryonic axes reached 85 % following the three-step process, compared with 70 % for the two-step process.

Matched MeSH terms: Citrus/embryology*
Fulltext Evaluation of reference genes at different developmental stages for quantitative real-time PCR in Aedes aegypti

Dzaki N, Ramli KN, Azlan A, Ishak IH, Azzam G

Sci Rep, 2017 03 16;7:43618.
PMID: 28300076 DOI: 10.1038/srep43618

The mosquito Aedes aegypti (Ae. aegypti) is the most notorious vector of illness-causing viruses such as Dengue, Chikugunya, and Zika. Although numerous genetic expression studies utilizing quantitative real-time PCR (qPCR) have been conducted with regards to Ae. aegypti, a panel of genes to be used suitably as references for the purpose of expression-level normalization within this epidemiologically important insect is presently lacking. Here, the usability of seven widely-utilized reference genes i.e. actin (ACT), eukaryotic elongation factor 1 alpha (eEF1α), alpha tubulin (α-tubulin), ribosomal proteins L8, L32 and S17 (RPL8, RPL32 and RPS17), and glyceraldeyde 3-phosphate dehydrogenase (GAPDH) were investigated. Expression patterns of the reference genes were observed in sixteen pre-determined developmental stages and in cell culture. Gene stability was inferred from qPCR data through three freely available algorithms i.e. BestKeeper, geNorm, and NormFinder. The consensus rankings generated from stability values provided by these programs suggest a combination of at least two genes for normalization. ACT and RPS17 are the most dependably expressed reference genes and therefore, we propose an ACT/RPS17 combination for normalization in all Ae. aegypti derived samples. GAPDH performed least desirably, and is thus not a recommended reference gene. This study emphasizes the importance of validating reference genes in Ae. aegypti for qPCR based research.

Matched MeSH terms: Aedes/embryology
Book: Genetics for obstetricians and gynaecologists: Chapter: Genetic markers on ultrasound scan

Sivanathan J, Thilaganathan B

Best Pract Res Clin Obstet Gynaecol, 2017 Jul;42:64-85.
PMID: 28456373 DOI: 10.1016/j.bpobgyn.2017.03.005

Prenatal diagnosis is a rapidly evolving speciality. Screening for aneuploidy begins with non-sonographic features of background risk of maternal age and past and family history. It is possible to diagnose major structural defects in the foetus using second trimester scans. Serum biochemistry markers in the early second trimester were added to increase the detection rate of aneuploidy. However, as some of these abnormalities were amenable to detection earlier in the first trimester, newer modalities were introduced. Nuchal translucency (NT) measurement was one of the main advances with regard to first trimester screening. Additional markers such as the presence of nasal bone, tricuspid regurgitation, ductus venosus and megacystis; together with first trimester serum biochemistry, further enhanced the detection rate of chromosomal abnormalities. Advances in research and technology have resulted in the availability of non-invasive prenatal testing from 10 weeks of gestation. This has facilitated the detection of the three major chromosomal aneuploidies at very early gestation. However, there are a wide range of genetic syndromes that are not confined to the main trisomies. There are specific markers on ultrasound that can be linked to specific syndromes. Hence, a structured and stepwise approach is needed to identify and reach a possible diagnosis. As anomalies are classified into malformations, deformations and disruptions, it is important to note that not all markers detected are due to genetic syndromes and not all genetic syndromes can be detected on ultrasound scan. In this chapter, we outline common structural markers and their association with main genetic syndromes.

Matched MeSH terms: Congenital Abnormalities/embryology
Preliminary studies on cryopreservation of snakehead (Channa striata) embryos

Mohd Sharifuddin M, Siti Azizah MN

Cryobiology, 2014 Aug;69(1):1-9.
PMID: 24726775 DOI: 10.1016/j.cryobiol.2014.04.001

This paper reports the findings of the ongoing studies on cryopreservation of the snakehead, Channa striata embryos. The specific objective of this study was to collect data on the sensitivity of C. striata embryo hatching rate to low temperatures at two different developmental stages in the presence of four different cryoprotectants. Embryos at morula and heartbeat stages were selected and incubated in 1M dimethyl sulfoxide (Me2SO), 1M ethylene glycol (EG), 1M methanol (MeOH) and 0.1M sucrose solutions at different temperatures for a period of time. Embryos were kept at 24 °C (control), 15 °C, 4 °C and -2 °C for 5 min, 1h and 3h. Following these treatments, the embryos were then transferred into a 24 °C water bath until hatch to evaluate the hatching rate. The results showed that there was a significant decrease of hatching rate in both developmental stages following exposure to 4 °C and -2 °C at 1h and 3h exposure in each treatment. Heartbeat stage was more tolerant against chilling at -2 °C for 3h exposure in Me2SO followed by MeOH, sucrose and EG. Further studies will be conducted to find the best method to preserve embryos for long term storage.

Matched MeSH terms: Fishes/embryology*
Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

Martin TE, Ton R, Niklison A

Ecol Lett, 2013 Jun;16(6):738-45.
PMID: 23473270 DOI: 10.1111/ele.12103

Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.

Matched MeSH terms: Songbirds/embryology*
Biolistic mediated production of transgenic oil palm

Kadir Ahmad Parveez G

Methods Mol Biol, 2008;477:301-20.
PMID: 19082956 DOI: 10.1007/978-1-60327-517-0_23

Physical and biological parameters affecting DNA delivery into oil palm embryogenic calli using the biolistic device are optimized. Five different promoters are also evaluated to identify the most suitable promoter for use in oil palm transformation. Finally, the effectiveness of kanamycin, geneticin (G418), neomycin, hygromycin, and herbicide Basta as selection agents to inhibit growth of oil palm embryogenic calli is evaluated. Combination of optimized parameters, best promoter and selection agent is later used to transform oil palm embryogenic calli for producing transgenic oil palm plants. Bombarded embryogenic calli are exposed to 50 mg/l of Basta after 3 weeks. Basta-resistant embryogenic calli started to emerge five to six months in medium containing Basta. The Basta-resistant embryogenic calli are proliferated until they reach a specific size, and the Basta-resistant calli are later individually isolated and regenerated to produce complete plantlets. The complete regenerated plantlets are evaluated for the presence of transgenes by PCR, Southern and thin layer chromatography analyses.

Matched MeSH terms: Arecaceae/embryology
Double neural tube defect: a case report and discussions on neural tube development

Vashu R, Liew NS

Childs Nerv Syst, 2010 May;26(5):697-701.
PMID: 20225088 DOI: 10.1007/s00381-010-1093-2

Double neural tube defect is a rare congenital problem. A case illustration and current literatures on neural tube closure theory are discussed. The available theories are summarised and compared with regard to the case report.

Matched MeSH terms: Neural Tube/embryology
Identification of a potential structural marker for embryogenic competency in the Brassica napus spp. oleifera embryogenic tissue

Namasivayam P, Skepper J, Hanke D

Plant Cell Rep, 2006 Sep;25(9):887-95.
PMID: 16568254

The Brassica napus secondary embryogenesis system requires no exogenous growth regulator to stimulate embryo development. It is stable embryogenically over a long period of culture and has a distinct pre-embryogenic stage. This system was used to investigate the morphological and cellular changes occurring in the embryogenic tissue compared to non-embryogenic tissue using various microscopy techniques. A unique ultrastructural feature designated the extracellular matrix (ECM) was observed on the surface of pre-embryogenic embryoids but not on the non-embryogenic individuals. The ECM layer was found to be dominant in the pre-embryogenic stage and reduced to fragments during embryo growth and development in mature embryogenic tissue. This is a novel aspect of the phenotype previously unreported in the Brassica system. This structure might be linked to acquisition of embryogenic competence.

Matched MeSH terms: Brassica napus/embryology*
Constructions of expression vectors of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) and transient expression of transgenes in immature oil palm embryos

Ariffin N, Abdullah R, Rashdan Muad M, Lourdes J, Emran NA, Ismail MR, et al.

Plasmid, 2011 Sep;66(3):136-43.
PMID: 21827784 DOI: 10.1016/j.plasmid.2011.07.002

Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is a polyhydroxyalkanoate (PHA) bioplastic group with thermoplastic properties is thus high in quality and can be degradable. PHBV can be produced by bacteria, but the process is not economically competitive with polymers produced from petrochemicals. To overcome this problem, research on transgenic plants has been carried out as one of the solutions to produce PHBV in economically sound alternative manner. Four different genes encoded with the enzymes necessary to catalyze PHBV are bktB, phaB, phaC and tdcB. All the genes came with modified CaMV 35S promoters (except for the tdcB gene, which was promoted by the native CaMV 35S promoter), nos terminator sequences and plastid sequences in order to target the genes into the plastids. Subcloning resulted in the generation of two different orientations of the tdcB, pLMIN (left) and pRMIN (right), both 17.557 and 19.967 kb in sizes. Both plasmids were transformed in immature embryos (IE) of oil palm via Agrobacterium tumefaciens. Assays of GUS were performed on one-week-old calli and 90% of the calli turned completely blue. This preliminary test showed positive results of integration. Six-months-old calli were harvested and RNA of the calli were isolated. RT-PCR was used to confirm the transient expression of PHBV transgenes in the calli. The bands were 258, 260, 315 and 200 bp in size for bktB, phaB, phaC and tdcB transgenes respectively. The data obtained showed that the bktB, phaB, phaC and tdcB genes were successfully integrated and expressed in the oil palm genome.

Matched MeSH terms: Arecaceae/embryology
Cryopreservation of whole seeds and excised embryonic axes of Citrus suhuiensis cv. limau langkat in accordance to their desiccation sensitivity

Makeen MA, Noor NM, Dussert S, Clyde MM

Cryo Letters, 2005 Jul-Aug;26(4):259-68.
PMID: 19827255

Following the investigation of desiccation sensitivity and freezing tolerance of the whole seed of Citrus suhuiensis cv. limau langkat, desiccation sensitivity and cryopreservation of the excised embryonic axes from the seeds of the same species were examined. Three drying conditions were employed: desiccation by equilibrium for the whole seeds and desiccation in laminar airflow and over silica gel for the excised embryonic axes. The relevance of desiccation sensitivity (WC50) to cryopreservation of whole seeds and excised axes was investigated. High desiccation tolerance (WC50 = 0.034 g H2O x g(-1)dw) was acquired for axes desiccated with faster dehydration rate (1.5 g x g(-1) x h(-1)) in laminar airflow compared to substantially lower desiccation tolerance (WC50 = 0.132 and 0.110 g H2O x g(-1)dw) acquired under slower dehydration rates (1.0 and 0.005 g x g(-1) x h(-1)) for axes desiccated over silica gel and whole seeds desiccated by equilibrium respectively. While few whole seeds (8.3%) survived freezing, high recovery percentages of axes (83.3% and 62.2%) after freezing were obtained under laminar airflow and silica gel drying conditions respectively. Irrespective of the drying method employed, axes survival percentages after exposure to LN temperature commensurate with the desiccation sensitivity pattern. For the whole seeds, a factor other than desiccation sensitivity that limits the tolerance to exposure to LN temperature seems to exist and still needs to be defined.

Matched MeSH terms: Citrus/embryology*
Fulltext Genetic transformation of Metroxylon sagu (Rottb.) cultures via Agrobacterium-mediated and particle bombardment

Ibrahim ER, Hossain MA, Roslan HA

Biomed Res Int, 2014;2014:348140.
PMID: 25295258 DOI: 10.1155/2014/348140

Sago palm (Metroxylon sagu) is a perennial plant native to Southeast Asia and exploited mainly for the starch content in its trunk. Genetic improvement of sago palm is extremely slow when compared to other annual starch crops. Urgent attention is needed to improve the sago palm planting material and can be achieved through nonconventional methods. We have previously developed a tissue culture method for sago palm, which is used to provide the planting materials and to develop a genetic transformation procedure. Here, we report the genetic transformation of sago embryonic callus derived from suspension culture using Agrobacterium tumefaciens and gene gun systems. The transformed embryoids cells were selected against Basta (concentration 10 to 30 mg/L). Evidence of foreign genes integration and function of the bar and gus genes were verified via gene specific PCR amplification, gus staining, and dot blot analysis. This study showed that the embryogenic callus was the most suitable material for transformation as compared to the fine callus, embryoid stage, and initiated shoots. The gene gun transformation showed higher transformation efficiency than the ones transformed using Agrobacterium when targets were bombarded once or twice using 280 psi of helium pressure at 6 to 8 cm distance.

Matched MeSH terms: Bony Callus/embryology
Fulltext TRANSPARENT TESTA GLABRA1 Regulates the Accumulation of Seed Storage Reserves in Arabidopsis

Chen M, Zhang B, Li C, Kulaveerasingam H, Chew FT, Yu H

Plant Physiol, 2015 Sep;169(1):391-402.
PMID: 26152712 DOI: 10.1104/pp.15.00943

Seed storage reserves mainly consist of starch, triacylglycerols, and storage proteins. They not only provide energy for seed germination and seedling establishment, but also supply essential dietary nutrients for human beings and animals. So far, the regulatory networks that govern the accumulation of seed storage reserves in plants are still largely unknown. Here, we show that TRANSPARENT TESTA GLABRA1 (TTG1), which encodes a WD40 repeat transcription factor involved in many aspects of plant development, plays an important role in mediating the accumulation of seed storage reserves in Arabidopsis (Arabidopsis thaliana). The dry weight of ttg1-1 embryos significantly increases compared with that of wild-type embryos, which is accompanied by an increase in the contents of starch, total protein, and fatty acids in ttg1-1 seeds. FUSCA3 (FUS3), a master regulator of seed maturation, binds directly to the TTG1 genomic region and suppresses TTG1 expression in developing seeds. TTG1 negatively regulates the accumulation of seed storage proteins partially through transcriptional repression of 2S3, a gene encoding a 2S albumin precursor. TTG1 also indirectly suppresses the expression of genes involved in either seed development or synthesis/modification of fatty acids in developing seeds. In addition, we demonstrate that the maternal allele of the TTG1 gene suppresses the accumulation of storage proteins and fatty acids in seeds. Our results suggest that TTG1 is a direct target of FUS3 in the framework of the regulatory hierarchy controlling seed filling and regulates the accumulation of seed storage proteins and fatty acids during the seed maturation process.

Matched MeSH terms: Arabidopsis/embryology
Postnatal growth rates covary weakly with embryonic development rates and do not explain adult mortality probability among songbirds on four continents

Martin TE, Oteyza JC, Mitchell AE, Potticary AL, Lloyd P

Am Nat, 2015 Mar;185(3):380-9.
PMID: 25674692 DOI: 10.1086/679612

Growth and development rates may result from genetic programming of intrinsic processes that yield correlated rates between life stages. These intrinsic rates are thought to affect adult mortality probability and longevity. However, if proximate extrinsic factors (e.g., temperature, food) influence development rates differently between stages and yield low covariance between stages, then development rates may not explain adult mortality probability. We examined these issues based on study of 90 songbird species on four continents to capture the diverse life-history strategies observed across geographic space. The length of the embryonic period explained little variation (ca. 13%) in nestling periods and growth rates among species. This low covariance suggests that the relative importance of intrinsic and extrinsic influences on growth and development rates differs between stages. Consequently, nestling period durations and nestling growth rates were not related to annual adult mortality probability among diverse songbird species within or among sites. The absence of a clear effect of faster growth on adult mortality when examined in an evolutionary framework across species may indicate that species that evolve faster growth also evolve physiological mechanisms for ameliorating costs on adult mortality. Instead, adult mortality rates of species in the wild may be determined more strongly by extrinsic environmental causes.

Matched MeSH terms: Songbirds/embryology*
Fulltext Toxicity of buprofezin on the survival of embryo and larvae of African catfish, Clarias gariepinus (Bloch)

Marimuthu K, Muthu N, Xavier R, Arockiaraj J, Rahman MA, Subramaniam S

PLoS One, 2013;8(10):e75545.
PMID: 24098390 DOI: 10.1371/journal.pone.0075545

Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (p< 0.05). However, the mortality was not significantly different (p<0.05) among the following concentrations: 0 (control), 0.05, 0.5 and 5 mg/L. Data obtained from the buprofezin acute toxicity tests were evaluated using probit analysis. The 24 h LC50 value (with 95% confidence limits) of buprofezin for embryos was estimated to be 6.725 (3.167-15.017) mg/L. The hatching of fish embryos was recorded as 68.8, 68.9, 66.9, 66.4, 26.9, 25.1 and 0.12% in response to 7 different concentrations of buprofezin, respectively. The mortality rate of larvae significantly (p<0.05) increased with increasing buprofezin concentrations exposed to 24-48 h. The 24 and 48 h LC50 values (with 95% confidence limits) of buprofezin for the larvae was estimated to be 5.702 (3.198-8.898) and 4.642 (3.264-6.287) mg/L respectively. There were no significant differences (p>0.05) in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L) of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish.

Matched MeSH terms: Catfishes/embryology*
Catalase and superoxide dismutase activities and the total protein content of protocorm-like bodies of Dendrobium sonia-28 subjected to vitrification

Poobathy R, Sinniah UR, Xavier R, Subramaniam S

Appl Biochem Biotechnol, 2013 Jul;170(5):1066-79.
PMID: 23640259 DOI: 10.1007/s12010-013-0241-z

Dendrobium sonia-28 is an important ornamental orchid in the Malaysian flower industry. However, the genus faces both low germination rates and the risk of producing heterozygous progenies. Cryopreservation is currently the favoured long-term storage method for orchids with propagation problems. Vitrification, a frequently used cryopreservation technique, involves the application of pretreatments and cryoprotectants to protect and recover explants during and after storage in liquid nitrogen. However, cryopreservation may cause osmotic injuries and toxicity to cryopreserved explants from the use of highly concentrated additives, and cellular injuries from thawing, devitrification and ice formation. Reactive oxygen species (ROS), occurring during dehydration and cryopreservation, may also cause membrane damage. Plants possess efficient antioxidant systems such as the superoxide dismutase (SOD) and catalase (CAT) enzymes to scavenge ROS during low temperature stress. In this study, protocorm-like bodies (PLBs) of Dendrobium sonia-28 were assayed for the total protein content, and both SOD and CAT activities, at each stage of a vitrification exercise to observe for deleterious stages in the protocol. The results indicated that cryopreserved PLBs of Dendrobium sonia-28 underwent excessive post-thawing oxidative stress due to decreased levels of the CAT enzyme at the post-thawing recovery stage, which contributed to the poor survival rates of the cryopreserved PLBs.

Matched MeSH terms: Dendrobium/embryology*

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