title: Dosage analysis of Z chromosome genes using microarray in silkworm, Bombyx mori.
abstract: In many organisms, dosage compensation is needed to equalize sex-chromosome gene expression in males and females. Several genes on silkworm Z chromosome were previously detected to show a higher expression level in males and lacked dosage compensation. Whether silkworm lacks global dosage compensation still remains poorly known. Here, we analyzed male:female (M:F) ratios of expression of chromosome-wide Z-linked genes in the silkworm using microarray data. The expression levels of genes on Z chromosome in each tissue were significantly higher in males compared to females, which indicates no global dosage compensation in silkworm. Interestingly, we also found some genes with no bias (M:F ratio: 0.8-1.2) on the Z chromosome. Comparison of male-biased (M:F ratio more than 1.5) and unbiased genes indicated that the two sets of the genes have functional differences. Analysis of gene expression by sex showed that M:F ratios were, to some extent, associated with their expression levels. These results provide useful clues to further understanding roles of dosage of Z chromosome and some Z-linked sexual differences in silkworms.
authors.affiliation: Southwest University, Beibei, Chongqing, China.
authors.forename: Xingfu
authors.initials: X
authors.lastname: Zha
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Xia
authors.forename: Jun
authors.initials: J
authors.lastname: Duan
authors.forename: Chunyun
authors.initials: C
authors.lastname: Wang
authors.forename: Ningjia
authors.initials: N
authors.lastname: He
authors.forename: Zhonghuai
authors.initials: Z
authors.lastname: Xiang
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D005260:Female; D018628:Gene Dosage; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000235:genetics; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D012727:Sex Characteristics; D012730:Sex Chromosomes / Q000235:genetics*
chemical_list: D019476:Insect Proteins