Characterization of serum complement activity of saltwater (Crocodylus porosus) and freshwater (Crocodylus johnstoni) crocodiles

Merchant, Mark; Britton, Adam

doi:10.1016/j.cbpa.2006.01.009

Cited by 69 publications

(77 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Activity was also significantly decreased at temperatures above 30°C, which supports past research, indicating that physiological processes in the alligator are optimized near this temperature (Merchant et al, 2003;Merchant et al, 2004). In a subsequent study, Merchant and Britton (Merchant and Britton, 2006) found that the lysis of sheep red blood cells by serum from saltwater (Crocodylus porosus) and freshwater (Crocodylus johnstoni) crocodiles required divalent metal ions, was heat sensitive and was unaffected by methylamine; therefore, suggesting that the alternative pathway was responsible for the lysis. The lysis occurred within 2min and reached maximum activity after 20min.…”

Section: Innate Immunitysupporting

confidence: 81%

“…While both endotherms and ectotherms experience seasonal variation in immune responses (Zapata et al, 1992;Martin et al, 2008), the magnitude and type of changes may differ because of the effect of temperature on immune responses. The immune systems of ectotherms are able to respond across a wide range of temperatures, but often with the strongest responses occurring at a certain species-specific temperature, with impaired responses at temperatures above and below that optimal temperature (Le Morvan et al, 1998;Mondal and Rai, 2001;Merchant et al, 2003;Merchant and Britton, 2006;Raffel et al, 2006). By contrast, for example, immune measurements of the red knot bird (Calidris canutus) varied seasonally but were not affected by temperature (Buehler et al, 2008).…”

Section: Why Study Ectotherms In Eco-immunology?mentioning

confidence: 99%

See 1 more Smart Citation

Understanding the vertebrate immune system: insights from the reptilian perspective

Zimmerman

Vogel

Bowden

2010

Journal of Experimental Biology

357

344

View full text Add to dashboard Cite

Summary Reptiles are ectothermic amniotes, providing the key link between ectothermic anamniotic fishes and amphibians, and endothermic amniotic birds and mammals. A greater understanding of reptilian immunity will provide important insights into the evolutionary history of vertebrate immunity as well as the growing field of eco-immunology. Like mammals, reptile immunity is complex and involves innate, cell-mediated and humoral compartments but, overall, there is considerably less known about immune function in reptiles. We review the current literature on each branch of the reptilian immune system, placing this information in context to other vertebrates. Further, we identify key areas that are prime for research as well as areas that are lagging because of lack of reagents in non-model systems.

show abstract

Section: Innate Immunitysupporting

confidence: 81%

Section: Why Study Ectotherms In Eco-immunology?mentioning

confidence: 99%

Understanding the vertebrate immune system: insights from the reptilian perspective

Zimmerman

Vogel

Bowden

2010

Journal of Experimental Biology

357

344

View full text Add to dashboard Cite

show abstract

“…Although we found no correlations between immune function and hemogregarine infection, we cannot rule out the possibility of hemogregarines or unmeasured pathogens contributing to age-related immune patterns. The absence of lysis and any age effect on agglutination in response to foreign antigens in painted turtles contrasts with research in other reptiles, which has demonstrated robust lytic activity against foreign antigens [crocodiles (Merchant and Britton, 2006); garter snakes (Sparkman and Palacios, 2009)] and increasing antibody activity with age [water pythons (Madsen et al, 2007); red-eared sliders (Zimmerman et al, 2010)]. It is possible that similar patterns may occur in painted turtles during the main active season (summer), if immune activity is more robust at that time.…”

Section: Discussion Age Effects: Development and Senescencementioning

confidence: 80%

State-dependent physiological maintenance in a long-lived ectotherm, the painted turtle (Chrysemys picta)

Schwanz

Warner

McGaugh

et al. 2011

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARYEnergy allocation among somatic maintenance, reproduction and growth varies not only among species, but among individuals according to states such as age, sex and season. Little research has been conducted on the somatic (physiological) maintenance of long-lived organisms, particularly ectotherms such as reptiles. In this study, we examined sex differences and age-and seasonrelated variation in immune function and DNA repair efficiency in a long-lived reptile, the painted turtle (Chrysemys picta). Immune components tended to be depressed during hibernation, in winter, compared with autumn or spring. Increased heterophil count during hibernation provided the only support for winter immunoenhancement. In juvenile and adult turtles, we found little evidence for senescence in physiological maintenance, consistent with predictions for long-lived organisms. Among immune components, swelling in response to phytohemagglutinin (PHA) and control injection increased with age, whereas basophil count decreased with age. Hatchling turtles had reduced basophil counts and natural antibodies, indicative of an immature immune system, but demonstrated higher DNA repair efficiency than older turtles. Reproductively mature turtles had reduced lymphocytes compared with juvenile turtles in the spring, presumably driven by a trade-off between maintenance and reproduction. Sex had little influence on physiological maintenance. These results suggest that components of physiological maintenance are modulated differentially according to individual state and highlight the need for more research on the multiple components of physiological maintenance in animals of variable states. Supplementary material available online at

show abstract

“…For instance, serum complement activities have been described for the American alligator [19], the freshwater and saltwater crocodiles [20], the broad-snouted caiman [21], and the American crocodile [22]. In addition, dipeptidyl peptidase IV activity has been characterized in the American alligator [23] and the American crocodile [24].…”

Section: Discussionmentioning

confidence: 99%

Comparison of Serum Phospholipase A2 Activities of All Known Extant Crocodylian Species

Merchant¹,

McAdon²,

Mead³

et al. 2017

ABC

Self Cite

View full text Add to dashboard Cite

Serum samples from all 23 extant crocodilian species were tested for phospholipase A 2 (PLA 2 ) activity against nine different bacterial species. The data were used to generate a PLA 2 activity profile for each crocodilian species, and the data were used to compare the activities of the three main lineages (Alligatoridae, Crocodylidae, and Gavialidae), the seven different genera, and to compare all of the 23 individual species. The data revealed that the three lineages of crocodilians (Alligatoridae, Crocodylidae, and Gavialidae) exhibited PLA 2 activities toward nine species of bacteria that were statistically distinguishable. In addition, the PLA 2 activities of crocodilians in a specific genus tended to be more similar to other members in their genus than to members of other crocodilian genera.

show abstract

Characterization of serum complement activity of saltwater (Crocodylus porosus) and freshwater (Crocodylus johnstoni) crocodiles

Cited by 69 publications

References 32 publications

Understanding the vertebrate immune system: insights from the reptilian perspective

Understanding the vertebrate immune system: insights from the reptilian perspective

State-dependent physiological maintenance in a long-lived ectotherm, the painted turtle (Chrysemys picta)

Comparison of Serum Phospholipase A2 Activities of All Known Extant Crocodylian Species

Contact Info

Product

Resources

About