Methods: In the present study, displacement loop (D-loop) sequences were used to evaluate the genetic relationship and diversity of seven tilapia populations that are widely cultured in China; this was done specifically to speculate on the maternal ancestry of red tilapia strains. Three red tilapia varieties of Oreochromis ssp., Taiwan (TW), Israel (IL), and Malaysia (MY) strains and other populations, including O. aureus (AR), O. niloticus (NL), O. mossambicus (MS), and the GIFT strain of O. niloticus, were collected and analyzed in this study.
Results: A total of 146 polymorphic sites and 32 haplotypes of D-loop sequences were detected among 332 fish and four major haplotypes were shared among the populations. The TW and NL populations had a greater number of haplotypes (20 and 8, respectively). The haplotype diversity (Hd) and nucleotide diversity (π) of each population ranged from 0.234 to 0.826, and 0 to 0.060, respectively. The significant positive Tajima's D value of neutral test were detected in the NL, IL, and MY populations (P 0.05). The nearest K2P genetic distance (D = 0.014) was detected between the MS and TW populations, whereas, the farthest (D = 0.101) was found between the GIFT and AR populations. The results from the molecular variance analysis (AMOVA) showed that there was an extremely significant genetic variation observed among the populations (P
METHOD: Potential references were identified through an English-language literature search using Medline, Psychinfo, Dissertation Abstracts (1966 to 1999) and through extensive manual searching of textbooks, reviews and reference lists.
RESULTS: The majority of studies related to EDs were conducted in Japan and China and a few were conducted in Singapore, Malaysia, Taiwan, and Korea whereas there was none in the Philippines, Laos, Vietnam, Cambodia, Myanmar, Indonesia and Thailand. Prevalence rates in Japan range from 0.025 to 0.030% for anorexia nervosa (AN) and from 1.9 to 2.9% for bulimia nervosa (BN). Community studies in China have found the AN prevalence to be 0.01% and BN rates ranging from 0.5% to 1.3%. These rates are lower than ED rates in the West (particularly the U.S. and Britain). Body dissatisfaction (BD) and dieting rates, however, were similar to those in the West. BD rates ranged from 68% (Taiwan) to 81% (Korea) and dieting rates ranged from 34% (Taiwan) to 68% (Japan). Sociocultural and developmental risk factors were relevant to this population.
CONCLUSIONS: EDs in Asian populations have received little attention because they have been predominantly viewed as associated with Western culture. Classified by many as a "culture-bound syndrome" of the West, they may really be a culture-change syndrome.