BackgroundThe genes boule and dazl are members of the DAZ (Deleted in Azoospermia) family encoding RNA binding proteins essential for germ cell development. Although dazl exhibits bisexual expression in mitotic and meiotic germ cells in diverse animals, boule shows unisexual meiotic expression in invertebrates and mammals but a bisexual mitotic and meiotic expression in medaka. How boule and dazl have evolved different expression patterns in diverse organisms has remained unknown.Methodology and Principal FindingsHere we chose the fish rainbow trout (Oncorhynchus mykiss) as a second lower vertebrate model to investigate the expression of boule and dazl. By molecular cloning and sequence comparison, we identified cDNAs encoding the trout Boule and Dazl proteins, which have a conserved RNA-recognition motif and a maximal similarity to their homologs. By RT-PCR analysis, adult RNA expression of trout boule and dazl is restricted to the gonads of both sexes. By chromogenic and two-color fluorescence in situ hybridization, we revealed bisexual and germline-specific expression of boule and dazl. We found that dazl displays conserved expression throughout gametogenesis and concentrates in the Balbinani's body of early oocytes and the chromatoid body of sperm. Surprisingly, boule exhibits mitotic and meiotic expression in the male but meiosis-specific expression in the female.ConclusionsOur data underscores differential conservation and divergence of DAZ family genes during vertebrate evolution. We propose a model in which the diversity of boule expression in sex and stage specificity might have resulted from selective loss or gain of its expression in one sex and mitotic germ cells.

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Accumulating evidence suggests that the hypothalamic-pituitary-adrenal (HPA) axis might play a major role in genetic susceptibility of aggressive behavior. The aim of the present study is to investigate the association between corticotrophin-releasing hormone receptor 1 (CRHR1) gene and aggressive behavior in Chinese southwest Han population. Participants consist of 282 healthy controls and 177 violent criminals (including robbery and intentional injury, which represent for aggressive behavior towards property and aggressive behavior towards others). Three tag single nucleotide polymorphisms (SNPs) of CRHR1 gene including rs4458044, rs242924, and rs1768996 were genotyped using improved multiplex ligase detection reaction (iMLDR) methods. Single-locus analysis revealed that none of the studied SNPs was significantly associated with the risk of aggressive behavior; however, haplotype analysis showed that a haplotype GGA significantly increased the susceptibility of aggressive behavior towards others with an odds ratios equal to 3.32 (p = 0.003). The present results, for the first time, indicate that the CRHR1 gene polymorphism is significantly associated with aggressive behavior in Chinese southwest Han population. Subjects with GGA haplotype have an increased susceptibility to aggressive behavior towards others.