Ultrastructure of Thyroid Gland in Hipposiderid Bat Hipposideros lankadiva (Kelaart)

摘要

In chiropterans, thyroid gland plays vital role during initial growth phase of life and in mobilizing the energy to overcome stress of puberty, pregnancy and lactation. Ultrastructural observation of the thyroid gland of hipposiderid bat Hipposideros lankadiva which undergoes the phenomenon of embryonic diapauses confirms the important role played by thyroid gland during diapause. The cuboidal follicular cells with well developed cell organelle and small follicular lumen during estrous, arousal and lactation period show active state of gland in nonpregnant female bat while flattened follicular cells with less developed cell organelle and large follicular lumen show hypothyroid condition in pregnant bat H. lankadiva undergoing diapause. Probably this maternal hypothyroid condition in pregnant animal regulates the embryonic diapause.