scholarly journals Clutch may predict growth of hatchling Burmese pythons better than food availability or sex

Biology Open ◽  
2021 ◽  
Vol 10 (11) ◽  
Author(s):  
Jillian M. Josimovich ◽  
Bryan G. Falk ◽  
Alejandro Grajal-Puche ◽  
Emma B. Hanslowe ◽  
Ian A. Bartoszek ◽  
...  

ABSTRACT Identifying which environmental and genetic factors affect growth pattern phenotypes can help biologists predict how organisms distribute finite energy resources in response to varying environmental conditions and physiological states. This information may be useful for monitoring and managing populations of cryptic, endangered, and invasive species. Consequently, we assessed the effects of food availability, clutch, and sex on the growth of invasive Burmese pythons (Python bivittatus Kuhl) from the Greater Everglades Ecosystem in Florida, USA. Though little is known from the wild, Burmese pythons have been physiological model organisms for decades, with most experimental research sourcing individuals from the pet trade. Here, we used 60 hatchlings collected as eggs from the nests of two wild pythons, assigned them to High or Low feeding treatments, and monitored growth and meal consumption for 12 weeks, a period when pythons are thought to grow very rapidly. None of the 30 hatchlings that were offered food prior to their fourth week post-hatching consumed it, presumably because they were relying on internal yolk stores. Although only two clutches were used in the experiment, we found that nearly all phenotypic variation was explained by clutch rather than feeding treatment or sex. Hatchlings from clutch 1 (C1) grew faster and were longer, heavier, in better body condition, ate more frequently, and were bolder than hatchlings from clutch 2 (C2), regardless of food availability. On average, C1 and C2 hatchling snout-vent length (SVL) and weight grew 0.15 cm d−1 and 0.10 cm d−1, and 0.20 g d−1 and 0.03 g d−1, respectively. Additional research may be warranted to determine whether these effects remain with larger clutch sample sizes and to identify the underlying mechanisms and fitness implications of this variation to help inform risk assessments and management. This article has an associated First Person interview with the first author of the paper.

2018 ◽  
Vol 19 (11) ◽  
pp. 3390 ◽  
Author(s):  
Sudip Paudel ◽  
Regan Sindelar ◽  
Margaret Saha

Accumulating evidence over the past three decades suggests that altered calcium signaling during development may be a major driving force for adult pathophysiological events. Well over a hundred human genes encode proteins that are specifically dedicated to calcium homeostasis and calcium signaling, and the majority of these are expressed during embryonic development. Recent advances in molecular techniques have identified impaired calcium signaling during development due to either mutations or dysregulation of these proteins. This impaired signaling has been implicated in various human diseases ranging from cardiac malformations to epilepsy. Although the molecular basis of these and other diseases have been well studied in adult systems, the potential developmental origins of such diseases are less well characterized. In this review, we will discuss the recent evidence that examines different patterns of calcium activity during early development, as well as potential medical conditions associated with its dysregulation. Studies performed using various model organisms, including zebrafish, Xenopus, and mouse, have underscored the critical role of calcium activity in infertility, abortive pregnancy, developmental defects, and a range of diseases which manifest later in life. Understanding the underlying mechanisms by which calcium regulates these diverse developmental processes remains a challenge; however, this knowledge will potentially enable calcium signaling to be used as a therapeutic target in regenerative and personalized medicine.


2020 ◽  
Vol 70 (4) ◽  
pp. 401-416
Author(s):  
Mao Jun Zhong ◽  
Long Jin ◽  
Jian Ping Yu ◽  
Wen Bo Liao

Abstract The expensive tissue hypothesis predicts a trade-off between investments in the brain and other energetically costly organs due to the costs associated with their growth and maintenance within the finite energy resources available. However, few studies address the strength of relationships between brain size and investments in precopulatory (ornaments and armaments) and postcopulatory (testes and ejaculates) sexual traits. Here, in a broad comparative study, we tested the prediction that the relationship between brain size and investment in sexual traits differs among taxa relative to the importance of sperm competition within them. We found that brain size was negatively correlated with sexual size dimorphism (SSD) in anurans and primates, and it tended to decrease with SSD in ungulates and cetaceans. However, brain size did not covary significantly with armaments (e.g., canine length, horn, antler, and muscle mass). Brain size was not correlated with postcopulatory sexual traits (testes and ejaculates). The intensity of covariance between brain size and precopulatory sexual traits decreased with increasing relative testis size.


Author(s):  
Purabi Kaushik ◽  
S. Banik ◽  
S. Naskar ◽  
K. Barman ◽  
A. A. Das ◽  
...  

The study was carried out on two different genetic groups of pig viz. Duroc and Hampshire maintained at pig breeding farm of National Research Centre on Pig, Guwahati. Effect of different genetic group and non-genetic factors (year and season of farrowing and parity) were estimated by least squares analysis of variance for different litter production, weight and pre weaning growth rate. Genetic group and parity revealed highly significant (P less than 0.01) effect on all the traits under study. However, effect of year and season of birth was non significant in most of the cases. The pre weaning mortality of Hampshire pigs was found to be less than Duroc. The performance of litter production and weight traits of Hampshire pigs were found to be better than Duroc pigs in the farm.


1994 ◽  
Vol 2 (4) ◽  
pp. 304-328 ◽  
Author(s):  
George T. Baker ◽  
George R. Martin

Aging is characterized by numerous physical, physiological, biochemical, and molecular changes. The rates at which aging processes occur are highly variable among individuals and are thought to be governed by both environmental and genetic factors. Lifestyle factors such as exercise, dietary, and smoking habits have been demonstrated to alter many of the changes usually associated with human aging. However, at present caloric restriction is the only experimental paradigm that has consistently been demonstrated in animal models to extend not only physiological vigor but also life span. The positive effects of exercise on physiological fitness and the reduction in the risks of certain diseases have been well documented. However, its effects on life span are not as clear. This article explores some of the basic mechanisms thought to be involved causally in the processes of aging, and outlines current and potential interventive strategies to retard or ameliorate the rates of decline in physiological function with advancing age.


Author(s):  
Daniel Hesselson ◽  
Denise S. Walker ◽  
Joshua Neil Massingham ◽  
William R. Schafer ◽  
G. Gregory Neely ◽  
...  

Chronic pain is a significant public health problem, affecting 20–25% of the global population, and there is a clear need for more specific and effective therapeutics. To achieve this, a comprehensive understanding of the underlying mechanisms and molecular machinery driving pain-related diseases is required. The definition of pain as an “unpleasant sensory and emotional experience” associated with tissue injury is innately anthropomorphic, the emotional element being difficult to reconcile in nonhuman organisms. Even simple invertebrates are nevertheless capable of nociception, the neural processing of noxious stimuli. With the significant advantages of simpler nervous systems, experimental tractability, and a high level of conservation, they have a major role to play in advancing our understanding. This chapter reviews our current molecular- and circuit-level understanding of nociception in two of the most widely used invertebrate experimental models, the nematode Caenorhabditis elegans and the fly Drosophila melanogaster. In particular, it summarizes the molecules, cells, and circuits that contribute to nociception in response to diverse noxious stimuli in these model organisms and the behavioral paradigms that we can harness to study them. The chapter discusses how mechanistic insights gained from these experimental systems can improve our understanding of pain in humans.


2016 ◽  
Vol 12 (9) ◽  
pp. 20160471 ◽  
Author(s):  
Kristian M. Forbes ◽  
Tapio Mappes ◽  
Tarja Sironen ◽  
Tomas Strandin ◽  
Peter Stuart ◽  
...  

Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles ( Microtus agrestis ) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal winter, using food supplementation and anthelmintic treatment of intestinal nematodes. Innate immune responses against intestinal parasite infections were compared between food-supplemented and non-supplemented voles. Voles with high food availability mounted stronger immune responses against intestinal nematode infections than food-limited voles. No food effects were seen in immune responses to intracellular coccidian parasites, possibly owing to their ability to avoid activation of innate immune pathways. Our findings demonstrate that food availability constrains vole immune responses against nematode infections, and support the concept that spatio-temporal heterogeneity in food availability creates variation in infectious disease susceptibility.


2021 ◽  
Vol 22 (13) ◽  
pp. 7112
Author(s):  
Barry J. Sessle

Chronic orofacial pain conditions can be particularly difficult to diagnose and treat because of their complexity and limited understanding of the mechanisms underlying their aetiology and pathogenesis. Furthermore, there is considerable variability between individuals in their susceptibility to risk factors predisposing them to the development and maintenance of chronic pain as well as in their expression of chronic pain features such as allodynia, hyperalgesia and extraterritorial sensory spread. The variability suggests that genetic as well as environmental factors may contribute to the development and maintenance of chronic orofacial pain. This article reviews these features of chronic orofacial pain, and outlines findings from studies in animal models of the behavioural characteristics and underlying mechanisms related to the development and maintenance of chronic orofacial pain and trigeminal neuropathic pain in particular. The review also considers the role of environmental and especially genetic factors in these models, focussing on findings of differences between animal strains in the features and underlying mechanisms of chronic pain. These findings are not only relevant to understanding underlying mechanisms and the variability between patients in the development, expression and maintenance of chronic orofacial pain, but also underscore the importance for considering the strain of the animal to model and explore chronic orofacial pain processes.


2021 ◽  
Vol 15 ◽  
Author(s):  
Laura Quintana ◽  
Cecilia Jalabert ◽  
H. Bobby Fokidis ◽  
Kiran K. Soma ◽  
Lucia Zubizarreta

Aggression is an adaptive behavior that plays an important role in gaining access to limited resources. Aggression may occur uncoupled from reproduction, thus offering a valuable context to further understand its neural and hormonal regulation. This review focuses on the contributions from song sparrows (Melospiza melodia) and the weakly electric banded knifefish (Gymnotus omarorum). Together, these models offer clues about the underlying mechanisms of non-breeding aggression, especially the potential roles of neuropeptide Y (NPY) and brain-derived estrogens. The orexigenic NPY is well-conserved between birds and teleost fish, increases in response to low food intake, and influences sex steroid synthesis. In non-breeding M. melodia, NPY increases in the social behavior network, and NPY-Y1 receptor expression is upregulated in response to a territorial challenge. In G. omarorum, NPY is upregulated in the preoptic area of dominant, but not subordinate, individuals. We hypothesize that NPY may signal a seasonal decrease in food availability and promote non-breeding aggression. In both animal models, non-breeding aggression is estrogen-dependent but gonad-independent. In non-breeding M. melodia, neurosteroid synthesis rapidly increases in response to a territorial challenge. In G. omarorum, brain aromatase is upregulated in dominant but not subordinate fish. In both species, the dramatic decrease in food availability in the non-breeding season may promote non-breeding aggression, via changes in NPY and/or neurosteroid signaling.


2018 ◽  
Author(s):  
Raimo Hartmann ◽  
Muriel C.F. van Teeseling ◽  
Martin Thanbichler ◽  
Knut Drescher

ABSTRACTProkaryotes display a remarkable spatiotemporal organization of processes within individual cells. Investigations of the underlying mechanisms rely extensively on the analysis of microscopy images. Advanced image analysis software has revolutionized the cell-biological studies of established model organisms with largely symmetric rod-like cell shapes. However’ algorithms suitable for analyzing features of morphologically more complex model species are lacking’ although such unusually shaped organisms have emerged as treasure-troves of new molecular mechanisms and diversity in prokaryotic cell biology. To address this problem’ we developed BacStalk’ a simple’ interactive’ and easy-to-use MatLab-based software tool for quantitatively analyzing images of commonly and uncommonly shaped bacteria’ including stalked (budding) bacteria. BacStalk automatically detects the separate parts of the cells (cell body’ stalk’ bud’ or appendage) as well as their connections’ thereby allowing in-depth analyses of the organization of morphologically complex bacteria over time. BacStalk features the generation and visualization of concatenated fluorescence profiles along cells’ stalks’ appendages’ and buds to trace the spatiotemporal dynamics of fluorescent markers. Cells are interactively linked to demographs’ kymographs’ cell lineage analyses’ and scatterplots’ which enables intuitive and fast data exploration and’ thus’ significantly speeds up the image analysis process. Furthermore’ BacStalk introduces a 2D representation of demo- and kymographs’ enabling data representations in which the two spatial dimensions of the cell are preserved. The software was developed to handle large data sets and to generate publication-grade figures that can be easily edited. BacStalk therefore provides an advanced image analysis platform that extends the spectrum of model organisms for prokaryotic cell biology to bacteria with multiple morphologies and life cycles.IMPORTANCEProkaryotic cells show a striking degree of subcellular organization. Studies of the underlying mechanisms and their variation among different species greatly enhance our understanding of prokaryotic cell biology. The image analysis software tool BacStalk extracts an unprecedented amount of information from images of stalked bacteria, by generating interactive demographs, kymographs, cell lineages, and scatter plots that aid fast and thorough data analysis and representation. Notably, BacStalk can preserve the two spatial dimensions of cells when generating demographs and kymographs to accurately and intuitively reflect the intracellular organization. BacStalk also performs well on established, non-stalked model organisms with common or uncommon shapes. BacStalk therefore contributes to the advancement of prokaryotic cell biology, as it widens the spectrum of easily accessible model organisms and enables a more intuitive and interactive data analysis and visualization.


Patan Pragya ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 97-104
Author(s):  
Usha Joshi ◽  
P. M. Shrestha ◽  
I. B. Karki ◽  
N. P. Chapagain ◽  
K. N. Poudyal

The solar energy is the abundantly available free and clean energy resources in Nepal. There are more than 300 sunny days because of Nepal lies in solar zone in a global map. The total solar radiation was measured by using CMP6 pyranometer at Nepalgunj (lat.:28.10oN, long.: 81.67oEand Alt. 165.0masl). The main objective of this study is to select the better empirical model and its empirical constants for the prediction of TSR for the year come. In this research, six different empirical models and meteorological parameters are utilized in the presence of regression technique for the years 2011 and 2012. Finally the different empirical constants are found. After the error analysis, the Swarthman-Oguniade model is found to perform better than others models. So the empirical constants of this model is utilized to predict the TSR of similar geographical sites of Nepal.


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