Differential effect of seasonal variation on lymphoid tissue of the lizard, Chalcides ocellatus

Hussein, Mohamed; Badir, N.; Ridi, Rashika El; Akef, Mamdouh S. A.

doi:10.1016/s0145-305x(78)80072-x

Cited by 54 publications

(9 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The histological study of the trout lymphoid organs did not pinpoint any obvious seasonal variations. In other poikilothermic animals studied, such as lizards and snakes (Hussein et a!., 1978(Hussein et a!., , 1979, there were marked seasonal variations in some of the lymphoid tissues, which led these workers to suggest that there were two distinct populations of lymphocytes in these species, with differing sensitivities to seasonal change. It would be worthwhile investigating this aspect further, on adult trout, to see if a seasonal (temperature) difference would reveal distinct lymphocyte populations.…”

Section: Discussionmentioning

confidence: 99%

Growth of the lymphoid organs in Rainbow trout, Salmo gairdneri from one to fifteen months of age

Tatner

Manning

1983

Journal of Zoology

View full text Add to dashboard Cite

The growth and cellular composition of the thymus, spleen and kidney were monitored in Rainbow trout, Salmo gairdneri, from 1 to 15 months of age. All organs grew as the fish grew, but they attained their maximum relative weights (expressed as a percentage of body weight) at 2–3 months ofage. The organ weights showed a closer correlation to body weight than they did to age. The total number of leucocytes in the lymphoid organs increased with age; however, the number per gram of lymphoid organ tissue, and per gram of tissue per gram of fish, decreased with age. The number of cells present showed a closer correlation to the weight of their respective organ, than they did to age. A histological study of the lymphoid organs showed gradual changes in the structure of the lymphoid tissues. The thymus showed some signs of involution even at 15 months of age. The spleen and kidney had mixed populations of erythrocytes and leucocytes, with a gradual increase in the amount of melanin as the fish aged. The kidney in particular had a rich variety of leucocytes. The blood picture showed no obvious fluctuations with age or season over the period studied, with the proportion of lymphocytes present remaining remarkably constant.

show abstract

Section: Discussionmentioning

confidence: 99%

Growth of the lymphoid organs in Rainbow trout, Salmo gairdneri from one to fifteen months of age

Tatner

Manning

1983

Journal of Zoology

View full text Add to dashboard Cite

show abstract

“…Most of the work investigating seasonal effects on immunity in reptiles has focused on histological and morphological changes to organs and cells of the immune system and not functional changes in immune responses (Hussein et al 1978;Zapata et al 1992;Munoz & De la Fuente 2004). However, researchers have begun to characterize some of the functional differences in both innate and adaptive responses (Munoz et al 2000;Munoz & De la Fuente 2001Zimmerman et al 2010a).…”

Section: Tlr Agonists Induce Responses In Isolated Tuatara Leukocytesmentioning

confidence: 99%

Toll-like receptor responses in tuatara

Flamme

Thierry

O'Neill

et al. 2010

New Zealand Journal of Zoology

View full text Add to dashboard Cite

Toll-like receptors (TLR) are an evolutionarily-conserved family of pattern recognition receptors that are a key component of innate immune responses. To understand if leukocytes from tuatara (Sphenodon punctatus), an evolutionarily distinct reptile species, expressed TLR, we isolated blood leukocytes from tuatara and analysed their ability to respond to known TLR2, TLR3, TLR4, and TLR7/8 agonists. We found that all tuatara could respond to these agonists but that responses were significantly greater in leukocytes isolated in summer compared to winter. Additionally, these impaired innate responses correlated with a reduction in monocytes during winter. The finding that tuatara have impaired innate responses during winter has important implications for conservation and in particular, for the relocation of animals.

show abstract

“…There is either a single seasonallyassociated peak in lymphoid organ development or there are two peak seasons of increased development of the lymphoid organs during any given year. For the lizards Chalcides ocellatus (Hussein et al, 1978a), Mabuya quinquetaeniata, Uromastyx aegyptia (Hussein et al, 1978b) and Scincus scincus (Hussein et al, 1979b), summer represents the season of maximal development of the lymphoid organs and the greatest number of lymphocytes. In winter, these lizards exhibit an involuted thymus and a spleen depleted of white pulp -strong evidence that the amount of lymphoid tissue in both of these organs was significantly reduced.…”

Section: Seasonal Changes In Morphologymentioning

confidence: 99%

“…The seasonal involution of the thymus of reptiles associated with winter could explain the lack of cellular and humoral response in reptiles maintained at low temperatures (Hussein et al, 1978a). Eumeces schneideri kept at low temperatures develops antibodies at a lower rate than animals maintained at high temperatures.…”

Section: Temperaturementioning

confidence: 99%

Biology of stress: interactions with reproduction, immunology and intermediary metabolism

GuilletteJr.¹,

Cree²,

Rooney³

1995

Health and Welfare of Captive Reptiles

View full text Add to dashboard Cite

Animals must maintain a steady physiological state, homeostasis, in response to a changing environment. An understanding of the stress response is essential if one is to appreciate the complex physiological mechanisms maintaining homeostasis in vertebrates. Moreover, a comprehensive understanding of the biology of stress is essential if we are to reduce stress in the care of any vertebrate species, induding those that are not domesticated and traditional laboratory animals.The goals of this chapter are to review our knowledge of the phenomenon of the physiological stress response in vertebrates generally, and then to describe in detail the limited information available on the biology of stress in reptiles. We shall not deal with psychic or emotional considerations of stress in reptiles. Specifically, we focus on the interactions between the physiological stress response and reproduction, immune function and intermediary metabolism. These three areas are critical to any husbandry and captive management programme. If not prevented or countermanded, the detrimental aspects of the stress response mounted by, for example,

show abstract

Differential effect of seasonal variation on lymphoid tissue of the lizard, Chalcides ocellatus

Cited by 54 publications

References 11 publications

Growth of the lymphoid organs in Rainbow trout, Salmo gairdneri from one to fifteen months of age

Growth of the lymphoid organs in Rainbow trout, Salmo gairdneri from one to fifteen months of age

Toll-like receptor responses in tuatara

Biology of stress: interactions with reproduction, immunology and intermediary metabolism

Contact Info

Product

Resources

About