The male and female reproductive apparatus of Zorotypus magnicaudelli (Malaysia), Zorotypus huxleyi (Ecuador) and Zorotypus weidneri (Brazil) were examined and documented in detail. The genital apparatus and sperm of the three species show only minor differences. The testes are larger in Z. magnicaudelli. Z. huxleyi lacks the helical appendage in the accessory glands. A long cuticular flagellum is present in Z. magnicaudelli and in the previously studied Zorotypus caudelli like in several other species, whereas it is absent in Z. weidneri, Z. huxleyi, Zorotypus hubbardi, Zorotypus impolitus and Zorotypus guineensis. Characteristic features of the very similar sperm are the presence of: a) two dense arches above the axoneme; b) a 9 + 9+2 axoneme with detached subtubules A and B of doublets 1 and 6; c) the axonemal end degenerating with enlarging accessory tubules; d) accessory tubules with 17 protofilaments; e) three accessory bodies beneath the axoneme; and f) two mitochondrial derivatives of equal shape. The first characteristic (a) is unknown outside of Zoraptera and possibly autapomorphic. The sperm structure differs distinctly in Z. impolitus and Z. hubbardi, which produce giant sperm and possess a huge spermatheca. The presence of the same sperm type in species either provided with a sclerotized coiled flagellum in males or lacking this structure indicates that a different organization of the genital apparatus does not necessarily affect the sperm structure. The flagellum and its pouch has probably evolved within Zoraptera, but it cannot be excluded that it is a groundplan feature and was reduced several times. The fossil evidence and our findings suggest that distinct modifications in the genital apparatus occurred before the fragmentation of the Gondwanan landmass in the middle Cretaceous.
Three new species of the uncommonly encountered insect order Zoraptera are described and figured from Peninsular Malaysia--Zorotypus magnicaudelli sp. n., Zorotypus cervicornis sp. n., and Zorotypus impolitus sp. n. Another species from the region, identified as Zorotypus caudelli Karny, 1927, was also collected and is reevaluated herein based on new material. A brief discussion of characters used in zorapteran systematics is provided, and a key to the species of Peninsular Malaysia provided. This is the first report for the order Zoraptera from Peninsular Malaysia.
The egg structure of Zorotypus magnicaudelli, Zorotypus hubbardi and Zorotypus impolitus was examined and described in detail. Major characteristics of zorapteran eggs previously reported were confirmed in these species, with the partial exception of Z. impolitus: 1) a pair of micropyles at the equator of the egg's ventral side, 2) a honeycomb pattern on the egg surface, 3) a two-layered chorion, 4) micropylar canals running laterally, 5) a flap covering the inner opening of the micropylar canal and 6) no region specialized for hatching. These features are probably part of the groundplan of the order. Three groups (A-C) and two subgroups (A1 and A2) of Zoraptera can be distinguished based on characters of the reproductive apparatus including eggs. However, information for more species is needed for a reliable interpretation of the complex and apparently fast evolving character system. The egg of Z. impolitus presumably shows apomorphic characteristics not occurring in other species, a chorion without layered construction and polygonal surface compartments with different sculptures on the dorsal and ventral sides of the egg. Another feature found in this species, distinct enlargement of the micropyles, is also found in Z. hubbardi. The increased micropylar size is likely correlated with the giant spermatozoa produced by males of these two species. These two features combined with the large size of the spermatheca are arguably a complex synapomorphy of Z. hubbardi and Z. impolitus. The phylogenetic placement of Zoraptera is discussed based on the egg structure. A clade of Zoraptera + Eukinolabia appears most plausible, but the issue remains an open question.
The egg structure and outline of the embryonic development of Metallyticus splendidus of one of the basal Mantodea representatives, Metallyticidae, were described in the present study. The results obtained were compared with those from the previous studies, to reconstruct and discuss the groundplan of Mantodea and Dictyoptera. In M. splendidus, the egg is spheroidal, it has a convex ventral side at the center in which numerous micropyles are grouped, and it possesses a conspicuous hatching line in its anterior half. These are the groundplan features of mantodean eggs and the "grouped micropyles in the ventral side of the egg" are regarded as an apomorphic groundplan feature of Dictyoptera. A small circular embryo is formed by a simple concentration of blastoderm cells, which then undergoes embryogenesis of the typical short germ band type. Blastokinesis is of the "non-reversion type" and the embryo keeps its original superficial position and original orientation throughout embryonic development. During the middle stages of development, the embryo undergoes rotation around the egg's anteroposterior axis. These features are a part of the groundplan of Mantodea. It is uncertain whether sharing of the "non-reversion type" of blastokinesis by Mantodea and blaberoidean Blattodea can be regarded as homology or homoplasy.
Cellular microenvironments are generally sophisticated, but crucial for regulating the functions of human pluripotent stem cells (hPSCs). Despite tremendous effort in this field, the correlation between the environmental factors-especially the extracellular matrix and soluble cell factors-and the desired cellular functions remains largely unknown because of the lack of appropriate tools to recapitulate in vivo conditions and/or simultaneously evaluate the interplay of different environment factors. Here, a combinatorial platform is developed with integrated microfluidic channels and nanofibers, associated with a method of high-content single-cell analysis, to study the effects of environmental factors on stem cell phenotype. Particular attention is paid to the dependence of hPSC short-term self-renewal on the density and composition of extracellular matrices and initial cell seeding densities. Thus, this combinatorial approach provides insights into the underlying chemical and physical mechanisms that govern stem cell fate decisions.
Cellular microenvironments consist of a variety of cues, such as growth factors, extracellular matrices, and intercellular interactions. These cues are well orchestrated and are crucial in regulating cell functions in a living system. Although a number of researchers have attempted to investigate the correlation between environmental factors and desired cellular functions, much remains unknown. This is largely due to the lack of a proper methodology to mimic such environmental cues in vitro, and simultaneously test different environmental cues on cells. Here, we report an integrated platform of microfluidic channels and a nanofiber array, followed by high-content single-cell analysis, to examine stem cell phenotypes altered by distinct environmental factors. To demonstrate the application of this platform, this study focuses on the phenotypes of self-renewing human pluripotent stem cells (hPSCs). Here, we present the preparation procedures for a nanofiber array and the microfluidic structure in the fabrication of a Multiplexed Artificial Cellular MicroEnvironment (MACME) array. Moreover, overall steps of the single-cell profiling, cell staining with multiple fluorescent markers, multiple fluorescence imaging, and statistical analyses, are described.