ciało-człowieka: Y chromosome

Evidence: 100 • authority: 72

The Y chromosome is one of two sex chromosomes in therian mammals and other organisms. Along with the X chromosome, it is part of the XY sex-determination system, in which the Y is used for sex-determining as the presence of the Y chromosome typically causes offspring produced in sexual reproduction to develop phenotypically male. In mammals, the Y chromosome contains the SRY gene, which usually triggers the differentiation of male gonads. The Y chromosome is typically only passed from male parents to male offspring.

Evidence: 65 • authority: 92

The impact of P-Element-induced hybrid dysgenesis on the male germline in Drosophila simulans.. The P-element, a DNA transposon, has independently invaded two Drosophila species, accompanied by rapid evolution of suppression. In the germline, suppression is mediated primarily by maternally expressed piRNAs, a class of regulatory small RNAs associated with PIWI proteins. The offspring of females that lack P-element-specific piRNAs and males that contain P-elements suffer a syndrome of deleterious phenotypes, including sterility, genome rearrangements, gonadal atrophy, and mutations, while the offspring of the reciprocal cross are normal. These effects, collectively termed hybrid dysgenesis,…

Evidence: 65 • authority: 72

Y linkage, also known as holandric inheritance (from Ancient Greek ὅλος hólos, "whole" + ἀνδρός andrós, "male"), describes traits that are produced by genes located on the Y chromosome. It is a form of sex linkage. Y linkage can be difficult to detect. This is partly because the Y chromosome is small and contains fewer genes than the autosomal chromosomes or the X chromosome. It is estimated to contain about 200 genes. It was thought that the human Y chromosome has little importance. While the Y-chromosome is sex-determining in humans and some other species, not all genes that play a role in sex determination are Y-linked. The Y-chromosome, generally does not undergo genetic recombination e…

Evidence: 53 • authority: 80

Table 1: Percentage of <i>Ooencyrtus mirus</i> female and male offspring of parents reared at different temperatures. All offspring were reared at 26 °C.

Evidence: 53 • authority: 92

Female- or male-biased offspring generated by targeted distortion of sex chromosome transmission in the mouse.. In animal breeding, female or male progeny is preferred depending on the use of the animals. Especially in livestock, offspring with undesired sex is of low economic value and often culled. Here we achieve targeted sex ratio distortion in the mouse, leveraging components of a selfish supergene, the t-haplotype. Utilizing its central element, the t-complex-responder, we generate a highly "selfless" genetic element disabling transgenic sperm. When integrated on the X or Y chromosome, it results in a high prevalence of nontransgenic offspring of the desired sex. Our strategy overcome…

Evidence: 53 • authority: 72

Sex is the phenotypic trait of a sexually reproducing organism in producing gametes of one of two different sizes or shapes—male or female gametes. During sexual reproduction, a male and a female gamete fuse to form a zygote, which develops into an offspring that inherits traits from each parent. By convention, organisms that produce smaller gametes (spermatozoa, sperm) are called male, while organisms that produce larger gametes (ova, often called egg cells) are called female. An organism that produces both types of gamete is a hermaphrodite. Sex is often referred to as biological sex when using the word sex alone could be ambiguous with other meanings of sex. In non-hermaphroditic species…

Evidence: 53 • authority: 88

Emergence of male-biased genes on the chicken Z-chromosome: Sex-chromosome contrasts between male and female heterogametic systems: Figure 1.. There has been extensive traffic of male-biased genes out of the mammalian and Drosophila X-chromosomes, and there are also reports of an under-representation of male-biased genes on the X. This may reflect an adaptive process driven by natural selection where an autosomal location of male-biased genes is favored since male genes are only exposed to selection one-third of the time when X-linked. However, there are several alternative explanations to “out-of-the-X” gene movement, including mutational bias and a means for X-linked genes to escape meiot…

Evidence: 53 • authority: 80

Ribosomal DNA is frequently concentrated on only one X chromosome in permanently apomictic aphids, but this does not inhibit male determination