Premium
THE THYMUS GLANDS OF A MARSUPIAL, SETONIX BRACHYURUS (QUOKKA), AND THEIR ROLE IN IMMUNE RESPONSES
Author(s) -
Yadav M,
Stanley NF,
Waring H
Publication year - 1972
Publication title -
australian journal of experimental biology and medical science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0004-945X
DOI - 10.1038/icb.1972.28
Subject(s) - biology , histology , anatomy , marsupial , medulla , pouch , physiology , zoology , genetics
Summary The quokka ( Setonix brachyurus ) has two pairs of thymus glands showing different rates of postnatal growth. The superficial thymus grows rapidly in the quokka pouch young and attains a maximal size of about 1% of body weight at 160 days; the thoracic thymus gland represents less than 0·1% of the body weight of the quokka at 160 days. The superficial thymus is approximately 1,000% heavier than the thoracic thymus when both glands reach their peak weight at 200 days of age. Apart from these differences, the superficial and thoracic thymus glands of quokka pouch young of various ages are similar in histology and their rate of organogensis, and in both glands small lymphocytes make their first appearance 3–4 days after birth. Initially, in both pairs of thymuses more lymphocytes are present in the centre of the lobule than the periphery, but in young older than 10 days the cortex is densely packed with small lymphocytes, whereas the medulla has few lymphocytes. The thymus glands take on typical thymus features with the appearance of Hassall's corpuscles after the 20th day. In adults the thymus glands are atrophic.