All about the ancient tribes
Equus species possess widely varying diploid chromosome numbers, from 2n = 32 (Mountain zebra) to 66 (Przewalski’s horse).14 мая 2014 г.
List of organisms by chromosome countOrganism (Scientific name)Chromosome numberSable antelope (Hippotragus niger)46Reeves’s muntjac (Muntiacus reevesi)46Human (Homo sapiens)46Parhyale hawaiensis46
Analysis of the karyotype reveals any abnormalities in the number and morphology (shape) of the chromosomes. Horses have 64 chromosomes including 31 pairs called autosomes, plus two sex chromosomes: two X chromosomes in females and one X and one Y chromosome in males.
48
mare mule
A mule is the offspring of a male donkey (a jack) and a female horse (a mare). … The mule ends up with 63. Mules can be either male or female, but, because of the odd number of chromosomes, they can’t reproduce.
The organism with the highest chromosome number recorded in to date is estimated to be 1,440 (or 720 pairs) found in the adder’s tongue fern Ophioglossum reticulatum. Original text presents information as: “to date is 2n = ca. 1440 found in…”
Extremes: Smallest number: The female of a subspecies of the ant, Myrmecia pilosula, has one pair of chromosomes per cell. Its male has only one chromosome in each cell.
48,XXYY syndrome results from the presence of an extra copy of both sex chromosomes in each of a male’s cells (48,XXYY). Extra copies of genes on the X chromosome interfere with male sexual development, preventing the testes from functioning normally and reducing the levels of testosterone.
Fertility, sterility and rarity
Hinnies, being hybrids of those two species, have 63 chromosomes and are in the majority of cases sterile. The uneven number of chromosomes results in an incomplete reproductive system. … The male hinny or mule can and will mate, but the emission is not fertile.
When a stallion is used for pasture breeding, we know that a stallion will mate much more than 2 or 3 times per day. Sperm numbers per breeding will thus go down dramatically when multiple mares are in heat on any day.
A hinny is the offspring of a male horse and a female donkey (jennet or jenny). They are rarer than mules, which are the offspring of a male donkey (jackass or jack) and a female horse. Like the mule, the hinny is almost always sterile.
Abstract. The mitotic and meiotic chromosomes of the semiaquatic rodent Ichthyomys pittieri (Rodentia, Cricetinae) from Venezuela were analyzed by means of conventional staining and several banding techniques. The diploid chromosome number of this rare species is 2n = 92, which is the highest value known for mammals.
33 chromosomes