Regularities and irregularities in the structure of the seminiferous epithelium in the domestic fowl (Gallus domesticus). II. Co-ordination between germ cell associations.
It was investigated in the domestic fowl, whether a mechanism for a synchronous start of the proliferation of the differentiating spermatogonia in a transversely cut seminiferous tubule (called the "co-ordination" between germ cell association) operates effectively in this species. A trapezoid-shaped cellular association demarcated by two perpendiculars from the tubular lumen to the basement membrane was the unit of observation (provisionally called a "column" Each column is composed of a bundle of elongate spermatids and the neighbouring, various types of germ cells). The extent of closeness of the co-ordination was examined in a total of 2,650 columns, based on the continuity of the spermiogenic step-number of the youngest generation of spermatids within adjacent columns. In no case did all columns in a tubular cross section show the same-step spermatids. In most cases (50.2% of 2,650 columns), the same number was kept in only 2 to 6 adjacent columns. The arrangement of different but consecutive numbers (e.g., 1-2-3 or 1-2-1) was observed in a total of 882 columns. The co-ordination mechanism, therefore, is considered to work, albeit incomplete, among a limited number of adjacent columns in this species.
Tiba
T
T
Department of Theriogenology, Faculty of Agriculture, Gifu University, Japan.
Shimizu
Y
Y
Kita
I
I
Tsubota
T
T
D000818:Animals; D002645:Chickens / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D012670:Seminiferous Epithelium / Q000166:cytology*; D013087:Spermatids / Q000166:cytology*; D013090:Spermatocytes / Q000166:cytology*; D013091:Spermatogenesis