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Histological changes in the Testes of Two Strains of Mice: Effect
of Ecological Factors
E. Bin Dohaish* A.Ali** and S.Melebary*
*ZoologyDepartment, Girl’s collage, Jeddah, Saudi Arabia.
**Zoology Department, Faculty of Science, Alexandria University, Alexandria,
Egypt.
E-mail: awatefali@yahoo.com
Abstract
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Study was carried out to evaluate the effect of some ecological factors
as photoperiod, nutrition and competition as a negative inter-relation
between animals on testis parameters their histological structures by
using the five levels of spermatogenic index as an indicator of sexual
maturity in MFI strain of albino mice. The first experimental group was
reared alone (single strain) i.e. without competitors and in the second
experiment the mice were reared with another strain Balb/C (mixed
strains) i.e., with competitors. Present study revealed violent and
aggressive of individuals behavior in the presence of compitots and
retarded the gonadal activity and inhibited sexual efficiency. Exposure
to longer photoperiod increased the size of testes and accelerated
sexual maturity. Exposure to long photoperiods combined with high level
of food ,without competitors was considered the best environmental
conditions for the earlier sexual maturity of mice .While the sexual
maturity was retarded in mice exposed to shorter photoperiod and
insufficient food with competitors ,which lead to an atrophy in the
testes and delay the spermatogenic index at the third level in higher
ages .This state was considered unsuitable for the sexual maturity.
Key words: Testis, Photoperiodism, food levels, histology,
spermatic index, male mice.
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