scholarly journals Intraspecific macroscopic digestive anatomy of ring-tailed lemurs (Lemur catta), including a comparison of frozen and formalin-stored specimens

Primates ◽  
2020 ◽  
Author(s):  
Marcus Clauss ◽  
Jelscha Trümpler ◽  
Nicole L. Ackermans ◽  
Andrew C. Kitchener ◽  
Georg Hantke ◽  
...  

AbstractDigestive tract measurements are often considered species specific, but little information exists on the degree to which they change during ontogeny within a species. Additionally, access to anatomical material from nondomestic species is often limited, with fixed tissues possibly representing the only available source, though the degree to which this material is representative in terms of dimensions and weight is debatable. In the present study, the macroscopic anatomy of the digestive tract (length of intestinal sections, and tissue weights of stomach and intestines) of 58 Lemur catta [ranging in age from 1 month (neonates) to 25 years], which had been stored frozen (n = 27) or fixed in formalin (n = 31), was quantified. Particular attention was paid to the caecum and the possible presence of an appendix. The intraspecific allometric scaling of body mass (BM)0.46[0.40;0.51] for total intestine length and BM0.48[0.41;0.54] for small intestine length was higher than the expected geometric scaling of BM0.33, and similar to that reported in the literature for interspecific scaling. This difference in scaling is usually explained by the hypothesis that, to maintain optimal absorption, the diameter of the intestinal tube cannot increase geometrically. Therefore, geometric volume gain of increasing body mass is accommodated for by more-than-geometric length scaling. According to the literature, not all L. catta have an appendix. No appendix was found in the specimens in the present study. The proportions of length measurements did not change markedly during ontogeny, indicating that the proportions of the foetus are representative of those of the adult animal. By contrast, width and tissue-mass scaling of the caecum indicated disproportionate growth of this organ during ontogeny that was not reflected in its length. Compared to overall intraspecific variation, the method of storage (frozen vs. formalin) had no relevant impact on length or weight measurements.

2020 ◽  
Author(s):  
Marcus Clauss ◽  
Jelscha Trümpler ◽  
Nicole L. Ackermans ◽  
Andrew C. Kitchener ◽  
Georg Hantke ◽  
...  

AbstractDigestive tract measurements are often considered species-specific, but little information exists on the degree to which they change during ontogeny within species. Additionally, access to anatomical material from nondomestic species is often limited, with fixed tissues possibly representing the only available source, though the degree at which this material is representative in terms of dimensions and weight is debatable. In the present study, the macroscopic digestive tract anatomy (length of intestinal portions, and tissue weights of stomach and intestines) of n=58 Lemur catta (from neonates to 25 years of age) was quantified, of which 27 had been stored frozen and 31 fixed in formalin. Particular attention was paid to the caecum and the possible presence of an appendix. The intraspecific allometric scaling of body mass (BM)0.46[0.40;0.51] for total intestine length and BM0.48[0.41;0.54] for small intestine length was higher than the expected geometric scaling of BM0.33, similar to literature results on interspecific scaling. This difference in scaling is usually explained by the hypothesis that the diameter of the intestinal tube cannot increase geometrically, to maintain optimal absorption. Therefore, geometric volume gain of increasing body mass is accommodated by more-than-geometric length scaling. Literature describes L. catta as being variable with respect to the presence of an appendix. No appendix was found in specimens of the present study. The proportions of length measurements did not change markedly during ontogeny, indicating that proportions developed in the foetus are already representative for the adult animal. By contrast, width and tissue-mass scaling of the caecum indicated a disproportionate growth of this organ during ontogeny that was not reflected in its length. Compared to overall intraspecific variation, the method of storage (frozen vs. formalin) had no relevant impact on length or weight measurements.


1992 ◽  
Vol 70 (7) ◽  
pp. 1381-1388 ◽  
Author(s):  
John A. Virgl ◽  
François Messier

We quantified changes in body composition, external morphology, and digestive tract morphology during the growth and development of muskrats from two marsh environments in central Saskatchewan, Canada. A total of 141 individuals were analysed, with body masses ranging from 20 g (newborns) to >800 g (prior to first reproduction). The growth rate of the digestive tract in nursing young was rapid, and at weaning juveniles had attained 75% of adult large and small intestine length, but only approximately 20% of adult body mass. At birth, muskrats contained no fat tissue, but accumulated fat reserves during the early stages of nursing. Fat reserves were then exhausted during weaning. Protein content also exhibited marked variation during the nursing–weaning period. As juveniles matured, the proportion of protein and ash became relatively constant at approximately 25 and 4.5% of body mass, respectively. Conversely, the proportion of fat tissue continued to increase with body mass, and was inversely related to water content. The accumulation of fat reserves from autumn through early winter was similar to that exhibited by adults and was probably associated with the presence of energy-rich food. Growth generally ceased in mid-October. Prior to the start of the reproductive season, juveniles had attained 77% of adult body mass and 95% of adult skeletal size. The growth diapause in juveniles from mid-October through March may limit their access to primary breeding habitat the following spring.


2021 ◽  
Vol 288 (1944) ◽  
pp. 20202888
Author(s):  
María J. Duque-Correa ◽  
Daryl Codron ◽  
Carlo Meloro ◽  
Amanda McGrosky ◽  
Christian Schiffmann ◽  
...  

An often-stated ecomorphological assumption that has the status of ‘textbook knowledge’ is that the dimensions of the digestive tract correlate with diet, where herbivores—consuming diets of lower digestibility—have longer intestinal tracts than faunivores—consuming diets of higher digestibility. However, statistical approaches have so far failed to demonstrate this link. Here, we collated data on the length of intestinal sections and body mass of 519 mammal species, and test for various relationships with trophic, climatic and other biological characteristics. All models showed a strong phylogenetic signal. Scaling relationships with body mass showed positive allometry at exponents greater than 0.33, except for the caecum, which is particularly large in smaller species. Body mass was more tightly linked to small intestine than to large intestine length. Adding a diet proxy to the relationships increased model fit for all intestinal sections, except for the small intestine when accounting for phylogeny. Thus, the diet has a main effect on the components of the large intestine, with longer measures in herbivores. Additionally, measures of habitat aridity had a positive relationship with large intestine length. The small intestine was longer in species from colder habitats at higher latitudes, possibly facilitating the processing of peak intake rates during the growing season. This study corroborates intuitive expectations on digestive tract anatomy, while the dependence of significant results on large sample sizes and inclusion of specific taxonomic groups indicates that the relationships cannot be considered fixed biological laws.


Author(s):  
Keisuke Fukumura ◽  
Kenshiro Shikano ◽  
Yuaki Narimatsu ◽  
Eiko Iwakoshi-Ukena ◽  
Megumi Furumitsu ◽  
...  

Abstract We recently identified a novel hypothalamic small protein, named neurosecretory protein GL (NPGL), which is involved in energy homeostasis in birds and mammals. However, whether the action of NPGL is influenced by nutritional composition remains unknown. Thus, we investigated the effect of chronic intracerebroventricular infusion of NPGL for 13 days on feeding behavior and body mass gain under a normal chow diet (NC), high-fat diet, high-sucrose diet (HSD), and medium-fat/medium-sucrose diet (MFSD) in rats. NPGL stimulated food intake of NC and MFSD, especially during the light period. By contrast, NPGL decreased body mass gain under NC and increased total white adipose tissue mass in HSD- and MFSD-fed rats. These data suggest that the effects of NPGL on feeding behavior, body mass gain, and fat accumulation depend on nutrient type. Among them, sucrose in diets seems to contribute to fat accumulation elicited by NPGL.


2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Mikhaila A Smith ◽  
Jian Cui ◽  
Sumeet A Kheterpal ◽  
Daniel J Rader ◽  
Robert C Bauer

Tribbles-1 (TRIB1) was recently identified through genome-wide association studies as a novel mediator of plasma lipids and coronary artery disease in humans. While subsequent in vivo mouse work confirmed a role for hepatic TRIB1 in these associations, little is known about metabolic roles for extra-hepatic Trib1. Interestingly, SNPs near the TRIB1 gene are significantly associated with circulating adiponectin levels in humans, suggesting a metabolic role for adipose TRIB1 . To further investigate this, we generated adipose-specific Trib1 KO mice (Trib1_ASKO) by crossing Trib1 cKO mice to transgenic Adiponectin-Cre mice. Chow-fed Trib1_ASKO mice exhibited no differences in adipose tissue mass and overall body mass as compared to control littermates (N=8/group). However, Trib1_ASKO mice had reduced total (-16.9%, p <0.01), HDL (-16.7%, p <0.01), and non-HDL cholesterol (-17.3%, p =0.068), as well as plasma triglycerides (-28.6%, p <0.001) as compared to WT mice. Trib1_ASKO mice also had increased plasma adiponectin levels, a finding more pronounced in female mice (+33.3%, p <0.001) than in males (+16.4%, p =0.072). Despite this increase, transcript levels of adipoQ were moderately decreased in Trib1_ASKO mice, suggesting a post-transcriptional mode of regulation. Transcript and protein levels of C/EBPα, the best described target of Trib1 and a key regulator of adipogenesis, remained unchanged. To further investigate the metabolic consequences of adipose-specific KO of Trib1 , WT and Trib1_ASKO mice were fed high-fat diet (HFD, 45% kCal fat) for 12 weeks to induce obesity. HFD-fed Trib1_ASKO mice had reduced fasting plasma glucose (-22.3%, p <0.05), insulin (-38.2%, p <0.05), and glucose tolerance (-19.8% AUC, p <0.05) compared to control mice. Body mass and fat mass of HFD-fed Trib1_ASKO mice remained unchanged from WT, and the reductions in plasma lipids and increase in plasma adiponectin persisted in the HFD-fed state. In summary, we present here the first in vivo validation of the human genetic association between TRIB1 and plasma adiponectin, and provide evidence suggesting that adipose TRIB1 contributes to the genetic associations observed in humans between TRIB1 and multiple metabolic parameters.


2018 ◽  
pp. 68-97
Author(s):  
Douglas S. Glazier

In this chapter, I show how clutch mass, offspring (egg) mass, and clutch size relate to body mass among species of branchiopod, maxillipod, and malacostracan crustaceans, as well as how these important life history traits vary among major taxa and environments independently of body size. Clutch mass relates strongly and nearly isometrically to body mass, probably because of physical volumetric constraints. By contrast, egg mass and clutch size relate more weakly and curvilinearly to body mass and vary in inverse proportion to one another, thus indicating a fundamental trade-off, which occurs within many crustacean taxa as well. In general, offspring (egg) size and number and their relationships to body mass appear to be more ecologically sensitive and evolutionarily malleable than clutch mass. The body mass scaling relationships of egg mass and clutch size show much more taxonomic and ecological variation (log-log scaling slopes varying from near 0 to almost 1 among major taxa) than do those for clutch mass, a pattern also observed in other animal taxa. The curvilinear body mass scaling relationships of egg mass and number also suggest a significant, size-related shift in how natural selection affects offspring versus maternal fitness. As body size increases, selection apparently predominantly favors increases in offspring size and fitness up to an asymptote, beyond which increases in offspring number and thus maternal fitness are preferentially favored. Crustaceans not only offer excellent opportunities for furthering our general understanding of life history evolution, but also their ecological and economic importance warrants further study of the various factors affecting their reproductive success.


Oecologia ◽  
2001 ◽  
Vol 128 (2) ◽  
pp. 303-303
Author(s):  
Atle Mysterud ◽  
F. Pérez-Barbería ◽  
Iain Gordon

2018 ◽  
Vol 65 (6) ◽  
pp. 627-631 ◽  
Author(s):  
Yan-Fu Qu ◽  
Shu-Zhan Zhao ◽  
Xu-Fei Jiang ◽  
Long-Hui Lin ◽  
Xiang Ji

Abstract We experimentally miniaturized freshly laid eggs of the Chinese cobra Naja atra (Elapidae) by removing ∼10% and ∼20% of original yolk. We tested if yolk-reduced eggs would produce 1) normal-sized hatchlings with invariant yolk-free body mass (and thus invariant linear size) but dramatically reduced or even completely depleted residual yolk, 2) smaller hatchlings with normal-sized residual yolk but reduced yolk-free body mass, or 3) smaller hatchlings of which both yolk-free body mass and residual yolk are proportionally reduced. Yolk quantity affected hatchling linear size (both snout-vent length and tail length) and body mass. However, changes in yolk quantity did not affect incubation length or any hatchling trait examined after accounting for egg mass at laying (for control and sham-manipulated eggs) or after yolk removal (for manipulated eggs). Specifically, yolk-reduced eggs produced hatchlings of which all major components (carcass, residual yolk, and fat bodies) were scaled down proportionally. We show that snakes cannot use yolk reserves to maximize their body size at hatching. Furthermore, our data also suggest that the partitioning of yolk in embryonic snakes is species-specific.


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