Selection at two sex-linked loci

Two sex-linked loci in the leopard frog, Rana pipiens.

Crosses involving one heterozygous parent were performed to test the inheritance of enzymes in the leopard frog, Rana pipiens. After metamorphosis, offspring were sexed and tissue extracts from them were analyzed by gel electrophoresis. Enzyme genotype and sex showed independent assortment for 10 of 12 enzymes heterozygous in the male parent. However, among the offspring of males heterozygous f...

Does natural selection increase or decrease variability at linked Loci.

An Overview of Sex Selection at Conception in Mammals

Although the mechanisms under which sex ratio is controlled in nature remain unknown, researchers have attempted to treat sperm in an effort to predetermine the sex of the offspring. The methods of sperm separation that have been repeatedly reported to isolate fractions rich in X- or Y-chromosome bearing sperm are serum albumin gradient swim-up and flow cytometry. However, the ability of the se...

Analysis and evolution of two functional Y-linked loci in a plant sex chromosome system.

White campion (Silene latifolia) is one of the few examples of plants with separate sexes and with X and Y sex chromosomes. The presence or absence of the Y chromosome determines which type of reproductive organs--male or female--will develop. Recently, we characterized the first active gene located on a plant Y chromosome, SlY1, and its X-linked homolog, SlX1. These genes encode WD-repeat prot...

Two sex-chromosome-linked microsatellite loci show geographic variance among North American Ostrinia nubilalis

PCR-based O. nubilalis population and pedigree analysis indicated female specificity of a (GAAAAT)n microsatellite, and male specificity of a CAYCARCGTCACTAA repeat unit marker. These loci were respectively named Ostrinia nubilalis W-chromosome 1 (ONW1) and O. nubilalis Z-chromosome 1 (ONZ1). Intact repeats of three, four, or five GAAAAT units are present among ONW1 alleles, and biallelic varia...