Silky sifaka (Propithecus candidus) “zzuss” vocalizations: Sexual dimorphism, individuality, and function in the alarm call of a monomorphic lemur

2012 ◽  
Vol 132 (3) ◽  
pp. 1799-1810 ◽  
Author(s):  
Erik R. Patel ◽  
Michael J. Owren
Keyword(s):  
Sexual Dimorphism ◽  
Alarm Call ◽  
And Function ◽  
Silky Sifaka

scholarly journals Sexual dimorphism in a top predator ( Notophthalmus viridescens ) drives aquatic prey community assembly

2018 ◽  
Vol 285 (1890) ◽  
pp. 20181717 ◽  
Author(s):  
Denon Start ◽  
Stephen De Lisle
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Intraspecific Variation ◽  
Structure And Function ◽  
Sexually Dimorphic ◽  
Ecological Communities ◽  
Top Predator ◽  
Aquatic Mesocosms ◽  
And Function ◽  
The Impact

Intraspecific variation can have important consequences for the structure and function of ecological communities, and serves to link community ecology to evolutionary processes. Differences between the sexes are an overwhelmingly common form of intraspecific variation, but its community-level consequences have never been experimentally investigated. Here, we manipulate the sex ratio of a sexually dimorphic predacious newt in aquatic mesocosms, then track their impact on prey communities. Female and male newts preferentially forage in the benthic and pelagic zones, respectively, causing corresponding reductions in prey abundances in those habitats. Sex ratio differences also explained a large proportion (33%) of differences in the composition of entire pond communities. Ultimately, we demonstrate the impact of known patterns of sexual dimorphism in a predator on its prey, uncovering overlooked links between evolutionary adaptation and the structure of contemporary communities. Given the extreme prevalence of sexual dimorphism, we argue that the independent evolution of the sexes will often have important consequences for ecological communities.

scholarly journals Reversed sexual dimorphism and altered prey base: the effect on sooty owl (Tyto tenebricosa tenebricosa) diet

2011 ◽  
Vol 59 (5) ◽  
pp. 302 ◽  
Author(s):  
Rohan J. Bilney ◽  
John G. White ◽  
Raylene Cooke
Keyword(s):  
Sexual Dimorphism ◽  
Small Mammals ◽  
Prey Availability ◽  
Mammalian Species ◽  
Control Programs ◽  
European Settlement ◽  
Mammal Conservation ◽  
Reversed Sexual Dimorphism ◽  
Conservation Concern ◽  
And Function

The ecology and function of many Australian predators has likely been disrupted following major changes in prey base due to declines in distribution and abundance of small mammals following European settlement. This study investigated various aspects of the dietary ecology of sooty owls (Tyto tenebricosa tenebricosa), including sexual variation as they potentially exhibit the greatest degree of reversed sexual dimorphism of any owl species worldwide. Sooty owls are highly opportunistic predators of non-volant small mammals, consuming most species known to exist in the region, so their diet fluctuates seasonally and spatially due to varying prey availability, and is particularly influenced by the breeding cycles of prey. Significant intersexual dietary differences existed with female sooty owls predominantly consuming much larger prey items than males, with dietary overlap at 0.62. The current reliance on relatively few native mammalian species is of conservation concern, especially when mammal declines are unlikely to have ceased as many threatening processes still persist in the landscape. Sooty owl conservation appears inextricably linked with small mammal conservation. Conservation efforts should be focussed towards improving prey densities and prey habitat, primarily by implementing control programs for feral predators and preventing the loss of hollow-bearing trees throughout the landscape.

Sex-related Differences in Gene Expression in Salivary Glands of BALB/c Mice

2005 ◽  
Vol 84 (2) ◽  
pp. 160-165 ◽  
Author(s):  
N.S. Treister ◽  
S.M. Richards ◽  
M.J. Lombardi ◽  
P. Rowley ◽  
R.V. Jensen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sexual Dimorphism ◽  
Salivary Glands ◽  
Structure And Function ◽  
Differentially Expressed ◽  
Male And Female ◽  
Tissue Specific ◽  
Total Rna ◽  
Males And Females ◽  
And Function

Sex-related differences exist in the structure and function of the major glands in a variety of species. Moreover, many of these variations appear to be unique to each tissue. We hypothesized that this sexual dimorphism is due, at least in part, to gland-specific differences in gene expression between males and females. Glands were collected from male and female BALB/c mice (n = 5/sex/experiment), and total RNA was isolated. Samples were analyzed for differentially expressed mRNAs with CodeLink microarrays, and data were evaluated by GeneSifter. Our results demonstrate that significant (P < 0.05) sex-related differences exist in the expression of numerous genes in the major salivary glands, and many of these differences were tissue-specific. These findings support our hypothesis that sex-related differences in the salivary glands are due, at least in part, to tissue-specific variations in gene expression.

Reproduction and development

2012 ◽  
Keyword(s):  
Sexual Dimorphism ◽  
Brain Structures ◽  
Sexual Differences ◽  
Tissue Type ◽  
Endocrine Control ◽  
Human Form ◽  
Form And Function ◽  
Sexual Characteristics ◽  
Males And Females ◽  
And Function

Reproduction and development are large topics, knowledge of which underpins several medical specialities including sexual health, fertility, gynaecology, urology, reproductive endocrinology, obstetrics, and neonatology. Doctors need to know the structure, function, and endocrine control of both male and female systems in order to diagnose and manage conditions specific to either male or female organs, as well as conditions such as impotence and infertility. Not surprisingly, the reproductive system is the only body system that shows major differences in both structure and function between males and females. However, sexual differences go beyond the primary sexual characteristics present at birth and the secondary sexual characteristics that emerge under the influence of sex hormones at puberty. Sexual dimorphism in some brain structures commences at an early age, and differences in the endocrine profiles of males and females produce characteristic changes in morphology, physiology, and behaviour that go beyond simple sexual dimorphism to affect many aspects of life, including sexual differences in susceptibility to disease and the longer life expectancy of women as compared to men that is seen around the world. Whether these differences, mainly beneficial to women, are because females are ‘biologically superior’ or because of a complex mix of genetic, behavioural, and social factors is a matter for discussion and research. Some knowledge of embryology is important to every medical student. As a minimum it provides explanations for the congenital malformations and their consequences that are encountered in many areas of clinical practice. Deeper knowledge will assist those seeking real insights into the structure of the human body. It is the study of embryological development and the knowledge of how each tissue type arises, how one tissue meets another, and how tissues move and change shape during development that explains the relations between tissues and organs in the adult human form. Achieving a full understanding of the dynamics of the formation of the body’s organs and tissues is demanding, but it can replace some of the rote learning of anatomical structures, familiar to many students, with a deeper understanding of form and function.

Sexual dimorphism of messenger RNA isolated from neonatal rat brain

1986 ◽  
Vol 109 (1) ◽  
pp. 23-NP ◽  
Author(s):  
I. M. Adcock ◽  
B. D. Greenstein
Keyword(s):  
Sexual Dimorphism ◽  
Rat Brain ◽  
Limbic System ◽  
Messenger Rna ◽  
Neonatal Rat ◽  
Transcriptional Level ◽  
Sexually Dimorphic ◽  
Clear Cut ◽  
And Function

ABSTRACT The rat brain is sexually dimorphic with respect to structure and function, and there is evidence that these differences are effected in the fetus through changes in protein synthesis, some of which may result from the intervention of gonadal steroids. To investigate this, messenger RNA (mRNA) from the limbic system and cerebellum of neonatal rats was prepared, translated in a rabbit reticulocyte system in vitro and the products were analysed by two-dimensional electrophoresis and fluorography. Some of the results were further analysed using image analysis. There was a striking sexual dimorphism in the patterns of incorporation of [35S]methionine into proteins using mRNA from the limbic system, in that groups of proteins were apparently present in male-but not in female-derived fluorograms and vice versa. One protein, tentatively identified from its coordinates as α-tubulin, was more abundant in male-derived fluorograms. Although there were no clear-cut qualitative sex differences using mRNA derived from the cerebellum, that derived from the male cerebellum appeared to be consistently more active. These results provide direct evidence for a sexual dimorphism at the transcriptional level in the neonatal limbic system of the rat. J. Endocr. (1986) 109, 23–28

scholarly journals Hydraulic constraints of reproduction do not explain sexual dimorphism in the genus Leucadendron (Proteaceae)

2017 ◽  
Author(s):  
Adam B. Roddy ◽  
Justin van Blerk ◽  
Jeremy J. Midgley ◽  
Adam G. West
Keyword(s):  
Sexual Dimorphism ◽  
Fire Frequency ◽  
Sexually Dimorphic ◽  
Hydraulic Efficiency ◽  
Costs Of Reproduction ◽  
Dioecious Species ◽  
Shoot Architecture ◽  
Males And Females ◽  
And Function ◽  
In Fire

AbstractBecause of the importance of reproduction in plant life history, the physiological costs of reproduction often influence vegetative structure and function. In dioecious species, these effects can be quite obvious, as different costs of male and female reproductive functions are entirely separated among different individuals in a population. In fire-prone ecosystems, in which recruitment is driven by fire frequency, many plants will maintain their seeds in the canopy, only to be released after a fire. The dioecious genus Leucadendron is a notable case of this, as females can maintain their seed cones for years, and, even more interestingly, species in the genus differ substantially in the degree to which males and females are sexually dimorphic. A recent study (Harris and Pannell 2010) argued that the hydraulic costs of maintaining seed cones for many years would effect the degree of sexual dimorphism among species. However, this assumed that shoot hydraulic architecture would be related to traits exhibiting sexual dimorphism. Here we explicitly test this hypothesis on two Leucadendron species. We found (1) that metrics of branch ramification used in the previous study to characterize dimorphism do not conform to known scaling relationships and (2) that sexual dimorphism in shoot architecture has no effect on hydraulic efficiency. Both of these results seriously question the pattern described by Harris and Pannell (2010) and suggest that the hydraulic costs of prolonged seed retention in Leucadendron do not significantly affect branch architecture.

No sexual dimorphism in limb muscles of a frog not engaging in amplexus

2013 ◽  
Vol 63 (4) ◽  
pp. 397-405
Author(s):  
Lixia Zhang ◽  
Yunyun Zhao ◽  
Jie Yang ◽  
Xin Lu ◽  
Xiaohong Chen
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Scramble Competition ◽  
Sexual Differences ◽  
Limb Muscle ◽  
Form And Function ◽  
Hindlimb Muscles ◽  
Limb Muscles ◽  
Forelimb Muscles ◽  
And Function

Sexual dimorphism in limb muscles is widespread among anurans, with males having stronger limbs than females. This phenomenon has been interpreted in the context of intrasexual selection: 1) the robust forelimb muscles in males are associated with amplexus, in which the male tries to grasp the female tightly, and also with rejection of rivals’ attempts at taking over, and 2) massive hindlimb muscles favor the ability to kick away rivals during scramble competition. However, in a few species, fertilization occurs without any form of amplexus and in these species the limb muscle dimorphism is expected to be absent. We tested this prediction inFeirana taihangnicus: a species without amplexus. As expected, we detected non-significant sexual differences in the mass of both forelimb and hindlimb muscles after accounting for body size and age. Our findings represent an interesting example of coevolution of form and function.

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