Organization of Seminiferous Epithelium in Primates: Relationship to Spermatogenic Efficiency, Phylogeny, and Mating System1

Abstract

The succession in time and space of specific germ cell associations, denoted as spermatogenic stages, is a typical feature of mammalian spermatogenesis. The arrangement of these stages is either single stage (one spermatogenic stage per tubular cross-section) or multistage (more than one spermatogenic stage per tubular cross-section). It has been proposed that the single-stage versus multistage arrangement is related to spermatogenic efficiency and that the multistage arrangement is typical for hominids. In the present work, the arrangement of spermatogenic stages and the spermatogenic efficiency of 17 primate species, comprising Strepsirrhini (Prosimians: Lemuriformes, Lorisiformes), Platyrrhini (New World primates), Catarrhini (Old World primates), and Hominoidea (great apes and humans), were analyzed comparatively by quantitative histological and flow cytometric means. We found a predominant single-stage tubular organization in the Strepsirrhini, indicating that the single-stage form represents the ancestral state. The highest degree of multistage complexity was found in Hominoidea (except orangutan) and in Platyrrhini, but not in Catarrhini. Hence, no direct relationship between single-stage/multistage tubular topography and phylogeny could be established across primates. In fact, the tubule arrangement seen in Platyrrhini and Catarrhini primates is the reverse of what might be expected from phylogeny. Interestingly, spermatogenic efficiency was similar in all species. We found no correlation between single-stage/multistage arrangement and spermatogenic efficiency or mating system. We speculate that the presence of a single-stage/multistage organization might simply reflect germ cell clonal size. Our findings further indicate that sperm competition in primates is not reflected at the level of testicular function.

Cloning of oestrogen receptor beta from Old and New World primates: identification of splice variants and functional analysis

“…Further studies are needed to determine if the inclusion of intronic sequences such as those seen in the macaque are replicated in other species. Interestingly, studies on the organisation of spermatogenesis in primate species have revealed that the marmoset more closely resembles the human than does the macaque , Wistuba et al 2003.…”

Male germline stem cells in non-human primates

“…For instance, a common hallmark of human and marmoset testes is that gonocytes are still present in the testes of a newborn until a couple of weeks after birth (Wistuba et al, 2003;Mitchell et al, 2008). This is in contrast to testes from newborn rhesus and cynomolgus monkeys, which contain type A spermatogonia as the predominant germ cell type (Simorangkir et al, 2005).…”

Molecular signatures to define spermatogenic cells in common marmoset (Callithrix jacchus)

“…First, the marmoset shows early sexual maturity (at around 1 year of age) and produces many offspring throughout its lifespan, which can provide researchers with much material and many opportunities for routine experiments. Secondly, marmoset testicular development is similar to that of humans (Millar et al 2000, Wistuba et al 2003, Li et al 2005, Mitchell et al 2008; for example, marmoset and human testes retain gonocytes even in newborns, but their persistence has not been observed in rhesus or cynomolgus monkeys (Wistuba et al 2004, Simorangkir et al 2005, Mitchell et al 2008, Albert et al 2010). Thirdly, it is possible to generate transgenic marmosets with germline transmission by lentiviral gene transduction ).…”

“…In adults, as in other mammals, spermatogenesis undergoes proliferative, meiotic, and spermiogenic phases to produce sperm (for review, see Li et al (2005)). Although the number of mitotic steps during spermatogenesis differs between marmoset and human (Millar et al 2000, Ehmcke et al 2006, they share many similarities in the organization and sequence of spermatogenic processes (Millar et al 2000, Wistuba et al 2003, Li et al 2005, Mitchell et al 2008. Thus, the common marmoset appears to be an appropriate experimental animal model for human testicular germ cell development.…”