A. Gottreich et al., Effect of photoperiod variation on testes and accessory sex organs in the male blind mole rat Spalax ehrenbergi, LIFE SCI, 67(5), 2000, pp. 521-529
The blind mole rat is a seasonally breeding fossorial rodent that is percep
tionally blind. This study examines the effect of photoperiod on the morpho
logy and histology of the male mole rat reproductive system. three groups o
f male mole rats were maintained in the laboratory under short day (SD) con
ditions (9L: 15D); long day (LD) conditions (15L:9D); and constant darkness
(CD), and compared to animals trapped in the field (FL). It was found that
the held animals revealed higher testes and prostate gland weights, higher
prostate tubuli volume (v(*)) and lower testes tubuli volume (v(*)) compar
ed to the other three groups. Distribution of the tubuli in the testes (Vv)
was low in the FL group compared to the SD and LD groups but still higher
than in the CD group. Distribution of lumen in the testes (Vv) was higher i
n the CD group in comparison to the other three groups. Distribution of int
erstitial tissue in the testes (Vv) was higher in the FL group than in the
other three groups. Electrolytes and elements secreted from the prostate gl
and did not differ among the four groups. In the FL group distribution of t
he tubuli (Vv) in the prostate gland was low and lumen ratio (Vv) was high
compared to the other three groups. Distribution of connective tissue in th
e prostate gland did not differ among all four groups. Testosterone levels
and total sperm count was highest in the FL group. Sperm production was not
ed in all groups; however spermatid and spermatozoa cell production was hig
her in the FL group. This study shows that photoperiod could be important i
n initiating timing in the breeding season but that certain other condition
s which are absent in the laboratory appear to be responsible for successfu
l breeding in the field. (C) 2000 Elsevier Science Inc. All rights reserved
.