Males and females experience differences in gene dose for loci in the nonrecombining region of heteromorphic sex chromosomes. If not compensated, this leads to expression imbalances, with the homogametic sex on average exhibiting greater expression due to the doubled gene dose. Many organisms with heteromorphic sex chromosomes display global dosage compensation mechanisms, which equalize gene e...

Sex differences in recombination are widespread in mammals, but the causes of this pattern are poorly understood. Previously, males from two interfertile subspecies of house mice, Mus musculus musculus and M. m. castaneus, were shown to exhibit a ∼30% difference in their global crossover frequencies. Much of this crossover rate divergence is explained by six autosomal loci and a large-effect lo...

In mammals, male sex determination, as well as spermatogenesis, is controlled by genes on the Y chromosome. Evolutionary comparisons may be used to detect and test candidate genes for these functions, under the hypothesis that the rapid evolution of the mammalian Y chromosome causes it to contain few genes other than those with a critical function in male reproduction. Comparisons of the gene c...

HE total genetic risk with respect to recessive lethal mutations in mammals can only be assessed if the mutability of sex chromosomes as well as autosomes is known. Therefore, a three-generation test was done in order to determine the incidence of recessive sex-linked lethal and detrimental mutations in mice. The frequency of autosomal recessives will be determined in subsequent experiments. Th...

Understanding the driving forces and molecular processes underlying dioecy and sex chromosome evolution, leading from hermaphroditism to the occurrence of male and female individuals, is of considerable interest in fundamental and applied research. The genus Phoenix, belonging to the Arecaceae family, consists uniquely of dioecious species. Phylogenetic data suggest that the genus Phoenix has d...

The natural sexes of the nematode Caenorhabditis elegans are the self-fertilizing hermaphrodite (XX) and the male (XO). The underlying genetic pathway controlling sexual phenotype has been extensively investigated. Mutations in key regulatory genes have been used to create a series of stable populations in which sex is determined not by X chromosome dosage, but in a variety of other ways, many ...

The chromosomes of male and female individuals Enteromius callipterus [1] were assessed in this study with the objective determining diploid chromosome karyotype. samples obtained from Tahoss River, Jos Plateau, assessment was conducted using conventional Giemsa staining technique. reveals that individual E. has a number 2n = 50, fundamental autosomal arms (NFa) 82, karyotype formula 14M + 4m 3...

Males of Zophobas aff. confusus and Nyctobates gigas (Tenebrionidae) collected in the State of Pernambuco, Brazil, were studied through conventional staining, C-banding, silver nitrate impregnation (AgNO₃), and the base specific fluorochromes CMA₃ and DAPI. Z. aff. confusus was found to have 2n = 20 (9+Xyp) while N. gigas exhibited 2n = 18 (8+neoXY). Large pericentromeric blocks of constitutive...