scholarly journals Possible Epigenetic Origin of a Recurrent Gynandromorph Pattern in Megachile Wild Bees

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 437
Author(s):  
Daniele Sommaggio ◽  
Giuseppe Fusco ◽  
Marco Uliana ◽  
Alessandro Minelli

Gynandromorphs, i.e., individuals with a mix of male and female traits, are common in the wild bees of the genus Megachile (Hymenoptera, Apoidea). We described new transverse gynandromorphs in Megachile pilidens Alfkeen, 1924 and analyze the spatial distribution of body parts with male vs. female phenotype hitherto recorded in the transverse gynandromorphs of the genus Megachile. We identified 10 different arrangements, nine of which are minor variants of a very general pattern, with a combination of male and female traits largely shared by the gynandromorphs recorded in 20 out of 21 Megachile species in our dataset. Based on the recurrence of the same gynandromorph pattern, the current knowledge on sex determination and sex differentiation in the honey bee, and the results of recent gene-knockdown experiments in these insects, we suggest that these composite phenotypes are possibly epigenetic, rather than genetic, mosaics, with individual body parts of either male or female phenotype according to the locally expressed product of the alternative splicing of sex-determining gene transcripts.

2019 ◽  
Vol 14 (7) ◽  
pp. 598-606
Author(s):  
Sarah Albogami

Background:: Regeneration is the process by which body parts lost as a result of injury are replaced, as observed in certain animal species. The root of regenerative differences between organisms is still not very well understood; if regeneration merely recycles developmental pathways in the adult form, why can some animals regrow organs whereas others cannot? In the regulation of the regeneration process as well as other biological phenomena, epigenetics plays an essential role. Objective:: This review aims to demonstrate the role of epigenetic regulators in determining regenerative capacity. Results:: In this review, we discuss the basis of regenerative differences between organisms. In addition, we present the current knowledge on the role of epigenetic regulation in regeneration, including DNA methylation, histone modification, lysine methylation, lysine methyltransferases, and the SET1 family. Conclusion:: An improved understanding of the regeneration process and the epigenetic regulation thereof through the study of regeneration in highly regenerative species will help in the field of regenerative medicine in future.


Reproduction ◽  
2018 ◽  
Author(s):  
Susana B Rulli ◽  
María Julia Cambiasso ◽  
Laura D Ratner

In mammals, the reproductive function is controlled by the hypothalamic-pituitary-gonadal axis. During development, mechanisms mediated by gonadal steroids exert an imprinting at the hypothalamic-pituitary level, by establishing sexual differences in the circuits that control male and female reproduction. In rodents, the testicular production of androgens increases drastically during the fetal/neonatal stage. This process is essential for the masculinization of the reproductive tract, genitals and brain. The conversion of androgens to estrogens in the brain is crucial for the male sexual differentiation and behavior. Conversely, feminization of the brain occurs in the absence of high levels of gonadal steroids during the perinatal period in females. Potential genetic contribution to the differentiation of brain cells through direct effects of genes located on sex chromosomes is also relevant. In this review, we will focus on the phenotypic alterations that occur on the hypothalamic-pituitary-gonadal axis of transgenic mice with persistently elevated expression of the human chorionic gonadotropin hormone (hCG). Excess of endogenously synthesized gonadal steroids due to a constant hCG stimulation is able to disrupt the developmental programming of the hypothalamic-pituitary axis in both transgenic males and females. Locally produced estrogens by the hypothalamic aromatase might play a key role in the phenotype of these mice. The “four core genotypes” mouse model demonstrated a potential influence of sex chromosome genes in brain masculinization before critical periods of sex differentiation. Thus, hormonal and genetic factors interact to regulate the local production of the neurosteroids necessary for the programming of the male and female reproductive function.


2012 ◽  
Vol 279 (1748) ◽  
pp. 4811-4816 ◽  
Author(s):  
Masaki Hoso

Autotomy of body parts offers various prey animals immediate benefits of survival in compensation for considerable costs. I found that a land snail Satsuma caliginosa of populations coexisting with a snail-eating snake Pareas iwasakii survived the snake predation by autotomizing its foot, whereas those out of the snake range rarely survived. Regeneration of a lost foot completed in a few weeks but imposed a delay of shell growth. Imprints of autotomy were found in greater than 10 per cent of S. caliginosa in the snake range but in only less than 1 per cent out of it, simultaneously demonstrating intense predation by the snakes and high efficiency of autotomy for surviving snake predation in the wild. However, in experiments, mature S. caliginosa performed autotomy less frequently. Instead of the costly autotomy, they can use defensive denticles on the inside of their shell apertures. Owing to the constraints from the additive growth of shells, most pulmonate snails can produce these denticles only when they have fully grown up. Thus, this developmental constraint limits the availability of the modified aperture, resulting in ontogenetic switching of the alternative defences. This study illustrates how costs of adaptation operate in the evolution of life-history strategies under developmental constraints


Author(s):  
Zackary A. Graham ◽  
Nicole Kaiser ◽  
Alexandre V. Palaoro

ABSTRACTIn many species, males possess specialized weaponry that have evolved to confer a benefit during aggressive interactions. Because male weaponry is typically an exaggerated or extreme version of pre-existing body parts, females often possess reduced or weaponry. Although much research has investigated sexual dimorphism in the sizes of such weapons, other weapon components, such as weapon performance or alternative weapon forms can also explain the evolution of weapon sexual dimorphisms. Here, we investigated the allometry and variation of multiple weapon components of hindleg weaponry in the male and female giant mesquite bugs, Thasus necalifornicus. Despite theory predicating greater allocation in male weaponry, we found that females allocated more into the lengths of their hindlegs compared to males. Despite this allocation, males possess relatively wider hindlegs, which likely increase area of muscle mass. Indeed, the squeezing performance of male hindlegs was much greater than that of female hindlegs. Lastly, we also described the allometry and variation in a male weapon component, prominent tibial spines, which likely are used to damage competitors during aggressive interaction. Overall, our findings highlight the intricacies of weapon sexual dimorphism and demonstrate the importance of measuring multiple weapon components and not a single measure.


Bothalia ◽  
2018 ◽  
Vol 48 (1) ◽  
Author(s):  
Judith T. Webber ◽  
Michelle D. Henley ◽  
Yolanda Pretorius ◽  
Michael J. Somers ◽  
Andre Ganswindt

Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection and processing may influence steroid concentrations, as faecal bacterial enzymes can alter steroid composition post-defaecation.Objectives: This study investigated changes in faecal glucocorticoid (fGCM), androgen (fAM) and progestagen (fPM) metabolite concentrations in faeces of a male and female African elephant (Loxodonta africana) post-defaecation and the influence of different faeces-drying regimes.Method: Subsamples of fresh faeces were frozen after being dried in direct sun or shade for 6, 20, 24, 48 and 72 h and 7 and 34 days. A subset of samples for each sex was immediately frozen as controls. Faecal hormone metabolite concentrations were determined using enzyme immunoassays established for fGCM, fAM and fPM monitoring in male and female African elephants.Results: Hormone metabolite concentrations of all three steroid classes were stable at first, but changed distinctively after 20 h post-defaecation, with fGCM concentrations decreasing over time and fPM and fAM concentrations steadily increasing. In freeze-dried faeces fGCM concentrations were significantly higher than respective concentrations in sun-dried material, which were in turn significantly higher than fGCM concentrations in shade-dried material. In contrast, fAM concentrations were significantly higher in sun- and shade-dried faeces compared to freeze-dried faeces. Higher fPM concentrations were also found in air-dried samples compared to lyophilised faeces, but the effect was only significant for sun-dried material.Conclusion: The revealed time restriction for collecting faecal material for hormone monitoring from elephants in the wild should be taken into account to assure reliable and comparable results. However, if logistics allow a timely collection, non-invasive hormone measurement remains a powerful and reliable approach to provide information about an elephant’s endocrine status.


2020 ◽  
Vol 17 (2) ◽  
pp. 81
Author(s):  
Van Basten Tambunan ◽  
Bandung Sahari ◽  
Damayanti Buchori ◽  
Purnama Hidayat

<p>The African oil palm weevil,<strong> </strong><em>Elaeidobius kamerunicus</em> is an effective pollinator of oil palm. Each individual palm produces exclusively male or female inflorescence so that the success of pollination depends on the ability of the pollinator to transfer pollen from male to female flowers. The objective of this research was to study the amount of pollen carried by <em>E. kamerunicus</em> between male and female inflorescences (pollen load) and the amount of pollen carried on each part of the weevil’s body (pollen distribution). Fifty each of male and female  <em>E. kamerunicus</em> individuals were collected from male and female flowers on trees in 3 locations: Siantar (North Sumatra), Dramaga (West Java), and Morowali (Central Sulawesi). Data on pollen load and pollen distribution on the weevil’s body were analyzed using <em>ImageJ</em> software. Results show that <em>E. kamerunicus</em> individuals collected more pollen from male flowers than from female flowers. In addition, male insects carried more pollen on their bodies than female insects. Pollen distribution on weevil body parts was highest on the elytra, followed by the thorax, abdomen, legs, and head respectively.</p>


2019 ◽  
Vol 9 (4) ◽  
pp. 752 ◽  
Author(s):  
Junhua Gu ◽  
Chuanxin Lan ◽  
Wenbai Chen ◽  
Hu Han

While remarkable progress has been made to pedestrian detection in recent years, robust pedestrian detection in the wild e.g., under surveillance scenarios with occlusions, remains a challenging problem. In this paper, we present a novel approach for joint pedestrian and body part detection via semantic relationship learning under unconstrained scenarios. Specifically, we propose a Body Part Indexed Feature (BPIF) representation to encode the semantic relationship between individual body parts (i.e., head, head-shoulder, upper body, and whole body) and highlight per body part features, providing robustness against partial occlusions to the whole body. We also propose an Adaptive Joint Non-Maximum Suppression (AJ-NMS) to replace the original NMS algorithm widely used in object detection, leading to higher precision and recall for detecting overlapped pedestrians. Experimental results on the public-domain CUHK-SYSU Person Search Dataset show that the proposed approach outperforms the state-of-the-art methods for joint pedestrian and body part detection in the wild.


The Condor ◽  
2000 ◽  
Vol 102 (2) ◽  
pp. 461-465 ◽  
Author(s):  
Kimberly J. Fernie ◽  
David M. Bird

AbstractWe studied nestling American Kestrels (Falco sparverius) in a laboratory setting to determine whether exposure to electromagnetic fields (EMFs) affected their growth. Captive nestlings were raised by their parents under control or EMF conditions similar to those occurring near transmission lines in the wild. Nestlings also were exposed to EMFs as embryos when incubated by their parents. Measurements of body mass, and lengths of tarsi, antebrachia, and feathers were taken every three days after hatching. EMF exposure affected the growth of female and male nestlings. EMF nestlings and fledglings were heavier and had longer tarsi. The periods of maximal weight gain and antebrachial growth were delayed in EMF males compared to controls, although EMF males were heavier and had similarly long antebrachia to controls by 21 days of age. Growth of ninth primaries and central rectrices of nestlings were unaffected by EMF exposure. Growth patterns of male and female kestrel nestlings were similar to those previously reported for this species, although the periods of maximal weight gain and bone growth did not occur earlier in EMF males than females as it did in controls.


Animals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 228
Author(s):  
Kenneth Boey ◽  
Kanae Shiokawa ◽  
Harutyun Avsaroglu ◽  
Sreekumari Rajeev

A pilot seroprevalence study was conducted to document exposure to selected pathogens in wild rats inhabiting the Caribbean island of St. Kitts. Serum samples collected from 22 captured wild rats (Rattus norvegicus and Rattus rattus) were tested for the presence of antibodies to various rodent pathogens using a rat MFI2 serology panel. The samples were positive for cilia-associated respiratory bacillus (13/22; 59.1%), Clostridium piliforme (4/22; 18.2%), Mycoplasma pulmonis (4/22; 18.2%), Pneumocystis carinii (1/22; 4.5%), mouse adenovirus type 2 (16/22; 72.7%), Kilham rat virus (15/22; 68.2%), reovirus type 3 (9/22; 40.9%), rat parvovirus (4/22; 18.2%), rat minute virus (4/22; 18.2%), rat theilovirus (2/22; 9.1%), and infectious diarrhea of infant rats strain of group B rotavirus (rat rotavirus) (1/22; 4.5%). This study provides the first evidence of exposure to various rodent pathogens in wild rats on the island of St. Kitts. Periodic pathogen surveillance in the wild rat population would be beneficial in assessing potential regional zoonotic risks as well as in enhancing the current knowledge when implementing routine animal health monitoring protocols in facilities with laboratory rodent colonies.


Author(s):  
Edward Polanco

Nahua peoples in central Mexico in the late postclassic period (1200–1521) and the early colonial period (1521–1650) had a sophisticated and complex system of healing known as tiçiyotl. Titiçih, the practitioners of tiçiyotl, were men and women that had specialized knowledge of rocks, plants, minerals, and animals. They used these materials to treat diseases and injuries. Furthermore, titiçih used tlapohualiztli (the interpretation of objects to obtain information from nonhuman forces) to ascertain the source of a person’s ailment. For this purpose, male and female titiçih interpreted cords, water, tossed corn kernels, and they measured body parts. Titiçih could also ingest entheogenic substances (materials that released the divinity within itself) to communicate with nonhuman forces and thus diagnose and prognosticate a patient’s condition. Once a tiçitl obtained the necessary information to understand his or her patient’s affliction, he or she created and provided the necessary pahtli (a concoction used to treat an injury, illness, or condition) for the infirm person. Finally, titiçih performed important ritual offerings before, during, and after healing that insured the compliance of nonhuman forces to restore and maintain their patients’ health.


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