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 the sex-determining because it is the presence or absence of Y chromosome that determines the male or female sex of offspring produced in sexual reproduction. In mammals, the Y chromosome contains the SRY gene, which triggers development of male gonads. The Y chromosome is passed only from male parents to male offspring.
Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars. They are sometimes known as meadow mice or field mice in North America.
The Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae. Some authorities place the subfamily Arvicolinae in the family Muridae along with all other members of the superfamily Muroidea. Some refer to the subfamily as the Microtinae or rank the taxon as a full family, the Arvicolidae.
The genus Arborimus is a group of voles found in western North America. The genus name is Latin for "tree mouse". Some sources include this genus with the heather voles, genus Phenacomys, and both are classified in the tribe Phenacomyini.
Chionomys is a genus of rodent in the family Cricetidae.
The Alai mole vole is a species of rodent in the family Cricetidae. It is known only from Kyrgyzstan, where it has been found in temperate grassland in the Alai Mountains. Little else is known about the vole.
The southern mole vole is a species of rodent in the family Cricetidae. It is found in Afghanistan, Iran, Pakistan, and Turkmenistan.
The Transcaucasian mole vole is a species of rodent in the family Cricetidae.
The northern mole vole is a species of rodent in the family Cricetidae. It is distributed over large parts of Eastern Europe and Asia.
The Zaisan mole vole, or eastern mole vole, is a species of rodent in the family Cricetidae. It is found in central Asia.
The creeping vole, sometimes known as the Oregon meadow mouse, is a small rodent in the family Cricetidae. Ranging across the Pacific Northwest of North America, it is found in forests, grasslands, woodlands, and chaparral environments. The small-tailed, furry, brownish-gray mammal was first described in the scientific literature in 1839, from a specimen collected near the mouth of the Columbia River. The smallest vole in its range, it weighs around 19 g (0.67 oz). At birth, they weigh 1.6 g (0.056 oz), are naked, pink, unable to open their eyes, and the ear flaps completely cover the ear openings. Although not always common throughout their range, there are no major concerns for their survival as a species.
The Ryukyu spiny rat is a species of rodent in the family Muridae. Endemic to Amami Ōshima island in the Amami Islands of the Ryukyu archipelago of Japan, its natural habitat is subtropical moist broadleaf forest. The karyotype has an odd diploid number, 2n = 25. Like its relative T. tokunoshimensis, it has lost its Y chromosome and SRY gene.
The Tokunoshima spiny rat is a rodent found only on the island of Tokunoshima in the Ryukyu Islands of Japan. Due to its small habitat, it is considered endangered. It is commonly found in the secondary and primary subtropical moist broadleaf forests of this island. The karyotype has an odd diploid number, 2n = 45. Like its relative T. osimensis, it is one of the few mammals that lack a Y chromosome and SRY gene.
