Basrur P K, Kanagawa H, Gilman J P
Can J Comp Med. 1969 Oct;33(4):297-306.
Cytogenetic and histological studies have been carried out on an intersex horse which was clinically diagnosed as a cryptorchid. The horse had the general conformation of a stallion but the external genitalia included a well developed vulva and a penis. The right testis which was descended was devoid of germ cells and the left "gonad" located in the cavum vaginale contained neither testicular nor ovarian tissue. The male duct system on both sides were relatively well developed despite the absence of a testis on the left side. Chromosome analysis on cultured cells from the descended testis revealed the presence of four chromosomally-distinct cell types with XX, XY, XXY and XO sex complements indicating a quadruple mosaicism. The presence of polymorphonuclear neutrophils exhibiting a drumstick, in the hemopoietic tissues and a sex chromatin body in the nucleated cells of buccal mucosa suggest that mosaicism prevails in other somatic tissues of the horse. On the basis of information derived from similar conditions in humans and some domestic animals it would appear that this horse resulted from an XXY zygote. The four cell types noted in the horse probably resulted through mitotic mechanisms favouring the loss of an X and a Y at different stages during embryonic development. The absence of gonad on the left side of this horse might be causally related to the preponderance of XO cell types in the somatic blastema during early gonadal differentiation.
对一匹临床诊断为隐睾的雌雄同体马进行了细胞遗传学和组织学研究。这匹马具有公马的一般外形，但外生殖器包括发育良好的阴门和阴茎。下降的右侧睾丸没有生殖细胞，位于阴道腔的左侧“性腺”既没有睾丸组织也没有卵巢组织。尽管左侧没有睾丸，但两侧的雄性管道系统发育相对良好。对来自下降睾丸的培养细胞进行染色体分析，发现存在四种染色体不同的细胞类型，其性染色体组成为XX、XY、XXY和XO，表明存在四重嵌合体。造血组织中出现具有鼓槌体的多形核中性粒细胞以及颊黏膜有核细胞中的性染色质体表明，嵌合体在马的其他体细胞组织中普遍存在。根据从人类和一些家畜的类似情况获得的信息，这匹马似乎是由XXY合子发育而来的。马中发现的四种细胞类型可能是通过有丝分裂机制产生的，在胚胎发育的不同阶段有利于X和Y的丢失。这匹马左侧性腺的缺失可能与早期性腺分化期间体细胞胚基中XO细胞类型占优势有因果关系。
