A morphological and endocrinological study of the male reproductive system of the thicktailed bush baby (galago garnetti)
Abstract
Eight male thick-tailed bush babies, Ga/ago garnetti,
were used in this study. Blood samples were obtained twice
a week from each animal, for a period of eight weeks.
Serum obtained from each sample was utilized in the
determination of testosterone (T) and luteinizing hormone
(LH) using radioimmunoassay and Leydig cell bioassay
respectively. There was significantly higher (p-cO .05) mean
serum T levels In the morning compared to evening hours.
lack of a definite rhythm of LH secretion during daytime, no
significant correlation between mean serum T and LH. and no
significant correlation between animal body weights and
mean Tvlevels during daytime.
Morphology of the reproductive system in this species
was studied. The gross structure was similar to those of
related species and othe~man primates.
Spermatogenesis was-st~uSing normal microscopy
techniques. Using semithin sections. twelve stages of the
seminiferous epithelial cycle, and seventeen steps of
spermatid development were identified. Stages I-IV of the
cycle was characterized by two generations of spermatids
and one of sperrnatocytes. Stage VI had a single generation
of both spermatocytes and spermatids. Stages VII-XII had a
single generation of spermatids and two of spermatocytes.
Spermiation in this species preceded the appearance of
preleptotene spermatocytes in the germinal epithelium.
Comparisons of the frequencies of the stages of the
seminiferous epithelial cycle in this species with other
mammals revealed, significantly close correlation (p<O.05)
between data obtained in this species and those of two
rodents and a monkey, and conversely disparity with those
of man and the baboon.
Fine structural examination of spermiogenesis III this
species focused on topographical relationships of the
chromatoid body and Golgi apparatus to the proacrosomal
granules, acrosome, nucleus and tail. It is proposed that the
ch ro mato id body may have an in teg ral ro Ie III early
acrosomal development.
Leydig cells and the basal cells of the vas deferens in
this species, exhibited unusual cytoplasmic crystalloid
inclusions.
The lining of the excurrent duct system was
characterized by presence of principal and basal cells. The
principal' cells had features of absorptive and synthetic
activity whose intensity varied along the duct. Basal cells
however, did not show any significant variation along the
duct system. Based on histological and fine structural
appearance, the epididymis in this species was divided into
six zones or regions. The morphology of the cells along the
excurrent ducts resembled those In other mammalian
species.
Three types of accessory sex glands namely, prostate,
vesicular and bulbourethral glands were evident. Fine
structural examination revealed possible differences In
secretory mechanisms in the three glands.
Citation
Master of SciencePublisher
University of Nairobi Department of Veterinary Anatomy