scholarly journals The genetics of morphological and behavioural island traits in deer mice

2018 ◽  
Author(s):  
Felix Baier ◽  
Hopi E. Hoekstra

ABSTRACTAnimals on islands often exhibit dramatic differences in morphology and behaviour compared to mainland individuals, a phenomenon known as the “island syndrome”. These differences are thought to be adaptations to island environments, but the extent to which they have a genetic basis or instead represent plastic responses to environmental extremes is often unknown. Here, we revisit a classic case of island syndrome in deer mice (Peromyscus maniculatus) from British Columbia. We first show that Saturna Island mice and those from neighbouring islands are ∼35% (∼5g) heavier than mainland mice and diverged approximately 10 thousand years ago. We then established laboratory colonies and find that Saturna Island mice are heavier both because they are longer and have disproportionately more lean mass. These trait differences are maintained in second-generation captive-born mice raised in a common environment. In addition, island-mainland hybrids reveal a maternal genetic effect on body weight. Using behavioural testing in the lab, we also find that wild-caught island mice are less aggressive than mainland mice; however, lab-raised mice born to these founders do not differ in aggression. Together, our results reveal that these mice respond differently to environmental conditions on islands – evolving both heritable changes in a morphological trait and also expressing a plastic phenotypic response in a behavioural trait.

2019 ◽  
Vol 286 (1914) ◽  
pp. 20191697 ◽  
Author(s):  
Felix Baier ◽  
Hopi E. Hoekstra

Animals on islands often exhibit dramatic differences in morphology and behaviour compared with mainland individuals, a phenomenon known as the ‘island syndrome’. These differences are thought to be adaptations to island environments, but the extent to which they have a genetic basis or instead represent plastic responses to environmental extremes is often unknown. Here, we revisit a classic case of island syndrome in deer mice ( Peromyscus maniculatus ) from British Columbia. We first show that Saturna Island mice and those from neighbouring islands are approximately 35% (approx. 5 g) heavier than mainland mice and diverged approximately 10 000 years ago. We then establish laboratory colonies and find that Saturna Island mice are heavier both because they are longer and have disproportionately more lean mass. These trait differences are maintained in second-generation captive-born mice raised in a common environment. In addition, island–mainland hybrids reveal a maternal genetic effect on body weight. Using behavioural testing in the laboratory, we also find that wild-caught island mice are less aggressive than mainland mice; however, laboratory-raised mice born to these founders do not differ in aggression. Together, our results reveal that these mice have different responses to the environmental conditions on islands—a heritable change in a morphological trait and a plastic response in a behavioural trait.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Neesha S. Patel ◽  
Ujwal R. Yanala ◽  
Shruthishree Aravind ◽  
Roger D. Reidelberger ◽  
Jon S. Thompson ◽  
...  

AbstractIn patients with short bowel syndrome, an elevated pre-resection Body Mass Index may be protective of post-resection body composition. We hypothesized that rats with diet-induced obesity would lose less lean body mass after undergoing massive small bowel resection compared to non-obese rats. Rats (CD IGS; age = 2 mo; N = 80) were randomly assigned to either a high-fat (obese rats) or a low-fat diet (non-obese rats), and fed ad lib for six months. Each diet group then was randomized to either underwent a 75% distal small bowel resection (massive resection) or small bowel transection with re-anastomosis (sham resection). All rats then were fed ad lib with an intermediate-fat diet (25% of total calories) for two months. Body weight and quantitative magnetic resonance-determined body composition were monitored. Preoperative body weight was 884 ± 95 versus 741 ± 75 g, and preoperative percent body fat was 35.8 ± 3.9 versus 24.9 ± 4.6%; high-fat vs. low fat diet, respectively (p < 0.0001); preoperative diet type had no effect on lean mass. Regarding total body weight, massive resection produced an 18% versus 5% decrease in high-fat versus low-fat rats respectively, while sham resection produced a 2% decrease vs. a 7% increase, respectively (p < 0.0001, preoperative vs. necropsy data). Sham resection had no effect on lean mass; after massive resection, both high-fat and low-fat rats lost lean mass, but these changes were not different between the latter two rat groups. The high-fat diet and low-fat diet induced obesity and marginal obesity, respectively. The massive resection produced greater weight loss in high-fat rats compared to low-fat rats. The type of dietary preconditioning had no effect on lean mass loss after massive resection. A protective effect of pre-existing obesity on lean mass after massive intestinal resection was not demonstrated.


2002 ◽  
Vol 11 (3) ◽  
pp. 205-217 ◽  
Author(s):  
Brenda K. Smith Richards ◽  
Brenda N. Belton ◽  
Angela C. Poole ◽  
James J. Mancuso ◽  
Gary A. Churchill ◽  
...  

The present study investigated the inheritance of dietary fat, carbohydrate, and kilocalorie intake traits in an F2 population derived from an intercross between C57BL/6J (fat-preferring) and CAST/EiJ (carbohydrate-preferring) mice. Mice were phenotyped for self-selected food intake in a paradigm which provided for 10 days a choice between two macronutrient diets containing 78/22% of energy as a composite of either fat/protein or carbohydrate/protein. Quantitative trait locus (QTL) analysis identified six significant loci for macronutrient intake: three for fat intake on chromosomes (Chrs) 8 ( Mnif1), 18 ( Mnif2), and X ( Mnif3), and three for carbohydrate intake on Chrs 17 ( Mnic1), 6 ( Mnic2), and X ( Mnic3). An absence of interactions among these QTL suggests the existence of separate mechanisms controlling the intake of fat and carbohydrate. Two significant QTL for cumulative kilocalorie intake, adjusted for baseline body weight, were found on Chrs 17 ( Kcal1) and 18 ( Kcal2). Without body weight adjustment, another significant kcal locus appeared on distal Chr 2 ( Kcal3). These macronutrient and kilocalorie QTL, with the exception of loci on Chrs 8 and X, encompassed chromosomal regions influencing body weight gain and adiposity in this F2 population. These results provide new insight into the genetic basis of naturally occurring variation in nutrient intake phenotypes.


2017 ◽  
Vol 25 (4) ◽  
pp. 329 ◽  
Author(s):  
M. Sakthivel ◽  
D. Balasubramanyam ◽  
P. Kumarasamy ◽  
H. Gopi ◽  
A. Raja ◽  
...  

The genetic parameters of growth traits in the New Zealand White rabbits kept at Sheep Breeding and Research Station, Sandynallah, The Nilgiris, India were estimated by partitioning the variance and covariance components. The (co)variance components of body weights at weaning (W42), post-weaning (W70) and marketing (W135) age and growth efficiency traits viz., average daily gain (ADG), relative growth rate (RGR) and Kleiber ratio (KR) estimated on a daily basis at different age intervals (42 to 70 d; 70 to 135 d and 42 to 135 d) from weaning to marketing were estimated by restricted maximum likelihood, fitting 6 animal models with various combinations of direct and maternal effects. Data were collected over a period of 15 yr (1998 to 2012). A log-likelihood ratio test was used to select the most appropriate univariate model for each trait, which was subsequently used in bivariate analysis. Heritability estimates for W42, W70 and W135 were 0.42±0.07, 0.40±0.08 and 0.27±0.07, respectively. Heritability estimates of growth efficiency traits were moderate to high (0.18 to 0.42). Of the total phenotypic variation, maternal genetic effect contributed 14 to 32% for early body weight traits (W42 and W70) and ADG1. The contribution of maternal permanent environmental effect varied from 6 to 18% for W42 and for all the growth efficiency traits except for KR2. Maternal permanent environmental effect on most of the growth efficiency traits was a carryover effect of maternal care during weaning. Direct maternal genetic correlations, for the traits in which maternal genetic effect was significant, were moderate to high in magnitude and negative in direction. Maternal effect declined as the age of the animal increased. The estimates of total heritability and maternal across year repeatability for growth traits were moderate and an optimum rate of genetic progress seems possible in the herd by mass selection. The genetic and phenotypic correlations among body weights and between growth efficiency traits were also estimated. Moderate to high heritability and higher genetic correlation in body weight traits promise good scope for genetic improvement provided measures are taken to keep the inbreeding at the lowest level.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 691-691 ◽  
Author(s):  
Catherine Johnson ◽  
Brooke Harbottle ◽  
Gabriella Hernandez ◽  
Victoria Smith ◽  
Morgan Coffin ◽  
...  

Abstract Objectives Non-alcoholic fatty liver disease (NAFLD) is a chronic metabolic disorder and the most common liver disease in pediatric populations. Epidemiological studies have observed a parallel increase in fructose consumption and incidence of NAFLD among children. The objective of this study was to compare the relative effect of inclusion of isocaloric amounts of high fructose corn syrup (66.5% fructose, 33.5% glucose) versus sucrose (50% fructose, 50% glucose) in the diet for 16 weeks on endpoints of NAFLD and insulin resistance. Methods 30-d-old Iberian pigs were housed in pairs and randomly assigned to receive solid diets (g/kg body weight × d) of 1) control (CON; n = 6): 0 g HFCS, 0 g SUC, and 174.03 kcal metabolizable energy (ME), 2) high-fructose corn syrup (HFCS; n = 8): 31.20 g high-fructose corn syrup, 0 g sucrose and 261 kcal ME, and 3) Sucrose (SUC; n = 6): 0 g high-fructose corn syrup, 24.04 g sucrose and 261 kcal ME for 16 consecutive weeks. Results Compared to CON, both HFCS and SUC diets increased body weight gain (P ≤ 0.001), relative liver weight (P ≤ 0.01) and leptin levels (P ≤ 0.01), and decreased percentage of lean mass composition in the animals (P ≤ 0.001). In addition, HFCS increased fasting insulin levels compared to CON (P ≤ 0.05), and decreased percentage lean mass compared to SUC (P ≤ 0.05). 75% of HFCS and 66.6% of SUC pigs showed histopathological lesions consistent with microvesicular steatosis with periportal or diffuse distribution. Serum markers of liver injury did not differ between diets, and none of the animals developed inflammation, hepatocellular ballooning, Mallory hyaline or necrosis in the liver. Metabolomics analysis revealed liver sorbitol and monosaccharide concentrations were higher in both the HFCS and SUC groups versus CON (P ≤ 0.05), while adenosine monophosphate (AMP) were higher and adenosine diphosphate levels lower in the HFCS and SUC in comparison to CON (P ≤ 0.05). Numerous phosphatidylcholines and sphingomyelins were differentially changed in the HFCS group versus CON (P ≤ 0.05). Conclusions Feeding diets high in either sucrose or high fructose corn syrup promoted obesity and steatosis in the animals. Further research is needed to investigate the mechanisms leading to increased insulin resistance in the HFCS group. Funding Sources ARI #58,873, AcornSeekers, STRIDE.


2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Johanna Christina Penell ◽  
David Mark Morgan ◽  
Penny Watson ◽  
Stuart Carmichael ◽  
Vicki Jean Adams

Abstract Background Overweight and obesity have been adversely associated with longevity in dogs but there is scarce knowledge on the relation between body composition and lifespan. We aimed to investigate the effects of body composition, and within-dog changes over time, on survival in adult Labradors using a prospective cohort study design. The dogs had a median age of 6.5 years at study start and were kept in similar housing and management conditions throughout. The effects of the various predictors, including the effect of individual monthly-recorded change in body weight as a time varying covariate, were evaluated using survival analysis. Results All dogs were followed to end-of-life; median age at end-of-life was 14.0 years. Body composition was measured annually with dual-energy x-ray absorptiometer (DEXA) scans between 6.2 and 17.0  years. All 39 dogs had DEXA recorded at 8, 9 and 10 years of age. During the study the mean (± SD) percent of fat (PF) and lean mass (PL) was 32.8 (± 5.6) and 64.2 (± 5.5) %, respectively, with a mean lean:fat ratio (LFR) of 2.1 (± 0.6); body weight (BW) varied from 17.5 to 44.0 kg with a mean BW change of 9.9 kg (± 3.0). There was increased hazard of dying for every kg increase in BW at 10 years of age; for each additional kg of BW at 10 years, dogs had a 19% higher hazard (HR = 1.19, P = 0.004). For the change in both lean mass (LM) and LFR variables, it was protective to have a higher lean and/or lower fat mass (FM) at 10 years of age compared to 8 years of age, although the HR for change in LM was very close to 1.0. For age at study start, older dogs had an increased hazard. There was no observed effect for the potential confounders sex, coat colour and height at shoulders, or of the time-varying covariate. Conclusions These results suggest that even rather late-life control efforts on body weight and the relationship between lean and fat mass may influence survival in dogs. Such “windows of opportunity” can be used to develop healthcare strategies that would help promote an increased healthspan in dogs.


2000 ◽  
Vol 22 (1) ◽  
pp. 9 ◽  
Author(s):  
ML Hale

The inheritance of geographic variation in body size in the southern brown bandicoot (Isoodon obesulus) was investigated through a common-environment crossbreeding experiment. The geographic variation in body size is related to habitat type, suggesting that it may be adaptive. Adults from two locations in Western Australia, Perth (large animals) and Albany (small animals), were collected and offspring from both hybrid and non-hybrid matings were reared under controlled conditions. All four variables examined (head length, pes length, ear length and body weight) were found to possess a large genetic component, supporting the interpretation that the geographic variation in size is adaptive. The three length variables initially showed additive genetic variation, although the variation in body weight displayed dominance. Genetically controlled differences in growth rate were also detected, with the smaller animals, found in the relatively poorer environment, possessing the faster intrinsic growth rate. Thus, not only does there appear to be adaptive divergence in initial body size, but the countergradient variation in growth rates provides additional evidence for adaptive divergence in this species.


2019 ◽  
Vol 9 (9) ◽  
pp. 1820 ◽  
Author(s):  
Shaanthana Subramaniam ◽  
Chin-Yi Chan ◽  
Ima-Nirwana Soelaiman ◽  
Norazlina Mohamed ◽  
Norliza Muhammad ◽  
...  

The prevalence of osteoporosis is forecasted to escalate in Malaysia with an increasing elderly population. This study aimed to analyze the prevalence and the risk factors of osteoporosis among middle-aged and elderly Chinese Malaysians. Three hundred sixty seven Malaysian Chinese aged ≥40 years in Klang Valley, Malaysia, were recruited. All subjects completed a structured questionnaire comprised of demographic details, medical history, diet, and lifestyle practices. Body anthropometry and bone mineral density measurements were also performed. The relationship between bone health status and risk factors was determined using multivariate logistic regression. Fifteen-point-three percent of the overall study population and 32.6% of those aged ≥71 years had osteoporosis. The prevalence of osteoporosis among women (18.9%) was higher than men (11.5%). The significant predictors of osteoporosis were age, body weight, and low monthly income. Lean mass, low education level, and being underweight predicted osteoporosis in women. Lean mass was the only significant predictor of osteoporosis in men. Overall, 15.3% of the Malaysian Chinese aged ≥40 years from Klang Valley, Malaysia, had osteoporosis. Osteoporosis was associated positively with increased age and low monthly income and negatively with body weight. Therefore, osteoporosis preventive strategies targeting Chinese elderly from a low socioeconomic background is necessary.


1996 ◽  
Vol 1996 ◽  
pp. 20-20
Author(s):  
J. H. Catterall ◽  
G. E. Pollott

Previous research into the genetics of broiler traits in a commercial breeding operation found a significant maternal effect on juvenile body weight, at 32 days of age, in addition to the additive genetic effect (Morris and Pollott, 1995). Since no nurture or imitative behaviour occurs between the dam and offspring in modem broiler production, any maternal effects are likely to be conferred to the offspring via the egg. This study attempts to investigate the nature of these effects.Pedigreed eggs from two separate broiler breeding lines, one experimental male line and one experimental female line, were individually weighed prior to incubation. In total 2871 eggs were weighed, 1887 eggs from the experimental female line and 984 eggs from experimental male line.


2017 ◽  
Vol 96 (6) ◽  
pp. 1553-1562 ◽  
Author(s):  
D.N.R.G. Kapell ◽  
P.M. Hocking ◽  
P.K. Glover ◽  
V.D. Kremer ◽  
S. Avendaño
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