Reproductive Potential Impacts Body Maintenance Parameters and Global DNA Methylation in Honeybee Workers (Apis mellifera L.)

The widely accepted hypothesis in life history evolution about the trade-off between fecundity and longevity is not confirmed by long-living and highly fecund queens in eusocial insects. The fact that the queens and facultatively sterile workers usually arise from genetically identical eggs but differ in DNA methylation makes them a good model for studies on senescence, eusocial evolution, and epigenetics. Therefore, honeybees seem to be especially useful here because of long living rebel-workers (RW) with high reproductive potential recently described. Longevity, ovariole number, nosema tolerance, and global DNA methylation have been assayed in normal workers (NW) versus RW in hives and cages. RW always lived longer than NW and unexpectedly extended longevity of NW when they were together, similarly as the presence of a queen did. RW lived longer despite the fact that they had higher Nosema spore load; surprisingly they became infected more easily but tolerated the infection better. Global DNA methylation increased with age, being lower in RW than in NW. Therefore, RW are queen-like considering global DNA methylation and the link between fecundity, longevity, and body maintenance. Presented features of RW expands possibilities of the use of honeybees as a model for studies on senescence, nosemosis, eusocial evolution, and epigenetics.

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Honeybee workers with higher reproductive potential have a greater learning ability

Apidologie ◽

10.1007/s13592-021-00847-9 ◽

2021 ◽

Author(s):

Karolina Kuszewska ◽

Wiktoria Rojek

Keyword(s):

Positive Impact ◽

Reproductive Potential ◽

Learning Ability ◽

Biological Functions ◽

Learning Skills ◽

Trade Off ◽

Individual Fitness ◽

Trade Offs ◽

Rebel Workers ◽

Separate Regression

AbstractLearning ability, which allows individuals to adjust their behaviour to changing environmental conditions, has a considerable positive impact on individual fitness. However, in addition to benefits, learning also incurs a cost, which means that investment in learning and maintaining learned skills can lead to trade-offs impacting other biological functions. Here, we tested whether a trade-off exists between learning skills and reproductive potential in honeybee workers. For this purpose, we compared learning ability between two groups of workers that differed in reproductive potential—normal and rebel workers. The results showed that workers with high reproductive potential (rebels), measured according to the number of ovarioles in the ovary, learned faster than normal workers with low reproductive potential. Moreover, by performing separate regression analyses within the rebel and non-rebel worker groups, we found that the reproductive potential of workers was positively correlated with their learning ability. The results show that in honeybees, there is no trade-off in resource allocation between two costly biological functions, learning and reproduction.

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Repeated loss of variation in insect ovary morphology highlights the role of developmental constraint in life-history evolution

10.1101/2020.07.07.191940 ◽

2020 ◽

Author(s):

Samuel H. Church ◽

Bruno A. S. de Medeiros ◽

Seth Donoughe ◽

Nicole L. Márquez Reyes ◽

Cassandra G. Extavour

Keyword(s):

Life History ◽

Nurse Cell ◽

Life History Evolution ◽

Trade Off ◽

Offspring Number ◽

Size Number ◽

History Of ◽

Insect Ovary ◽

Ovariole Number ◽

History Evolution

AbstractThe number of offspring an organism can produce is a key component of its evolutionary fitness and lifehistory. Here we perform a test of the hypothesized trade off between the number and size of offspring using thousands of descriptions of the number of egg-producing compartments in the insect ovary (ovarioles), a common proxy for potential offspring number in insects. In contrast to prior claims, we find that ovariole number is not generally negatively correlated with the size of insect eggs, and we highlight several factors that may have contributed to this size-number trade off being strongly asserted in previous studies. We reconstruct the evolutionary history of the nurse cell arrangement within the ovariole, and show that the diversification of ovariole number and egg size have both been largely independent of nurse cell presence or position within the ovariole. Instead we show that ovariole number evolution has been shaped by a series of transitions between variable and invariant states, with multiple independent lineages evolving to have almost no variation in ovariole number. We highlight the implications of these invariant lineages on our understanding of the specification of ovariole number during development, as well as the importance of considering developmental processes in theories of life-history evolution.

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Global DNA Methylation is influenced by smoking behavior

Pharmacopsychiatry ◽

10.1055/s-2007-991871 ◽

2007 ◽

Vol 40 (05) ◽

Author(s):

MAN Muschler ◽

T Hillemacher ◽

H Frieling ◽

S Moskau ◽

A Semmler ◽

...

Keyword(s):

Dna Methylation ◽

Smoking Behavior ◽

Global Dna Methylation

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Oxidative damage, inflammation, genotoxic effect, and global DNA methylation caused by inhalation of formaldehyde and the purpose of melatonin

Toxicology Research ◽

10.1093/toxres/tfaa079 ◽

2020 ◽

Vol 9 (6) ◽

pp. 778-789

Author(s):

Letícia Bernardini ◽

Eduardo Barbosa ◽

Mariele Feiffer Charão ◽

Gabriela Goethel ◽

Diana Muller ◽

...

Keyword(s):

Dna Methylation ◽

Bone Marrow ◽

Oxidative Damage ◽

Bronchoalveolar Lavage ◽

Bone Marrow Cells ◽

Histological Study ◽

Global Dna Methylation ◽

Protective Effects ◽

Global Methylation ◽

Protein Thiols

Abstract Formaldehyde (FA) exposure has been proven to increase the risk of asthma and cancer. This study aimed to evaluate for 28 days the FA inhalation effects on oxidative stress, inflammation process, genotoxicity, and global DNA methylation in mice as well as to investigate the potential protective effects of melatonin. For that, analyses were performed on lung, liver and kidney tissues, blood, and bone marrow. Bronchoalveolar lavage was used to measure inflammatory parameters. Lipid peroxidation (TBARS), protein carbonyl (PCO), non-protein thiols (NPSH), catalase activity (CAT), comet assay, micronuclei (MN), and global methylation were determined. The exposure to 5-ppm FA resulted in oxidative damage to the lung, presenting a significant increase in TBARS and NO levels and a decrease in NPSH levels, besides an increase in inflammatory cells recruited for bronchoalveolar lavage. Likewise, in the liver tissue, the exposure to 5-ppm FA increased TBARS and PCO levels and decreased NPSH levels. In addition, FA significantly induced DNA damage, evidenced by the increase of % tail moment and MN frequency. The pretreatment of mice exposed to FA applying melatonin improved inflammatory and oxidative damage in lung and liver tissues and attenuated MN formation in bone marrow cells. The pulmonary histological study reinforced the results observed in biochemical parameters, demonstrating the potential beneficial role of melatonin. Therefore, our results demonstrated that FA exposure with repeated doses might induce oxidative damage, inflammatory, and genotoxic effects, and melatonin minimized the toxic effects caused by FA inhalation in mice.

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Decreased expression of DNA methyltransferases in the testes of patients with non-obstructive azoospermia leads to changes in global DNA methylation levels

Reproduction Fertility and Development ◽

10.1071/rd18246 ◽

2019 ◽

Vol 31 (8) ◽

pp. 1386 ◽

Cited By ~ 1

Author(s):

Fatma Uysal ◽

Gokhan Akkoyunlu ◽

Saffet Ozturk

Keyword(s):

Dna Methylation ◽

Male Infertility ◽

De Novo ◽

Biological Effects ◽

Testicular Biopsy ◽

Round Spermatid ◽

Dna Methyltransferases ◽

Global Dna Methylation ◽

Obstructive Azoospermia ◽

Spermatogenic Cells

DNA methylation plays key roles in epigenetic regulation during mammalian spermatogenesis. DNA methyltransferases (DNMTs) function in de novo and maintenance methylation processes by adding a methyl group to the fifth carbon atom of the cytosine residues within cytosine–phosphate–guanine (CpG) and non-CpG dinucleotide sites. Azoospermia is one of the main causes of male infertility, and is classified as obstructive (OA) or non-obstructive (NOA) azoospermia based on histopathological characteristics. The molecular background of NOA is still largely unknown. DNA methylation performed by DNMTs is implicated in the transcriptional regulation of spermatogenesis-related genes. The aim of the present study was to evaluate the cellular localisation and expression levels of the DNMT1, DNMT3A and DNMT3B proteins, as well as global DNA methylation profiles in testicular biopsy samples obtained from men with various types of NOA, including hypospermatogenesis (hyposperm), round spermatid (RS) arrest, spermatocyte (SC) arrest and Sertoli cell-only (SCO) syndrome. In the testicular biopsy samples, DNMT1 expression and global DNA methylation levels decreased gradually from the hyposperm to SCO groups (P<0.05). DNMT3A expression was significantly decreased in the RS arrest, SC arrest and SCO groups compared with the hyposperm group (P<0.05). DNMT3B expression was significantly lower in the RS arrest and SCO groups than in the hyposperm group (P<0.05). Although both DNMT1 and DNMT3A were localised in the cytoplasm and nucleus of the spermatogenic cells, staining for DNMT3B was more intensive in the nucleus of spermatogenic cells. In conclusion, the findings suggest that significant changes in DNMT expression and global DNA methylation levels in spermatogenic cells may contribute to development of male infertility in the NOA groups. Further studies are needed to determine the molecular biological effects of the altered DNMT expression and DNA methylation levels on development of male infertility.

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Testicular Dnmt3 expression and global DNA methylation are down-regulated by gonadotropin releasing hormones in the ricefield eel Monopterus albus

Scientific Reports ◽

10.1038/srep43158 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 5

Author(s):

Yize Zhang ◽

Xin Sun ◽

Lihong Zhang ◽

Weimin Zhang

Keyword(s):

Dna Methylation ◽

Global Dna Methylation ◽

Monopterus Albus

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Potential effect of tobacco cigarettes smoking on global DNA methylation status and protamines transcripts in human spermatozoa

Middle East Fertility Society Journal ◽

10.1186/s43043-021-00066-3 ◽

2021 ◽

Vol 26 (1) ◽

Author(s):

Mohammed M. Laqqan ◽

Maged M. Yassin

Keyword(s):

Dna Methylation ◽

Cigarette Smoking ◽

Dna Fragmentation ◽

Methylation Status ◽

Human Spermatozoa ◽

Global Dna Methylation ◽

Transcription Level ◽

Heavy Smokers ◽

Protamine 1 ◽

Protamine 2

Abstract Background Epigenetics refers to an alteration in gene expression without alteration in the sequence of DNA and this process may be affected by environmental factors and lifestyle like cigarette smoking. This study was designed to evaluate the potential effect of cigarette smoking on the global DNA methylation status and the transcription level of protamine 1 and protamine 2 in human spermatozoa. A total of 188 semen samples were collected from men with a mean age of 34.9 ± 5.8 years old (98 heavy smokers and 90 non-smokers). The DNA and RNA were isolated from purified spermatozoa, then the status of global DNA methylation and the transcription level of protamine 1 and protamine 2 were evaluated using ELISA and qPCR, respectively. The chromatin non-condensation and DNA fragmentation in human spermatozoa were evaluated using chromomycin A3 staining and TUNEL assay, respectively. Results A significant increase has been found in the status of global DNA methylation in spermatozoa of heavy smokers compared to non-smokers (7.69 ± 0.69 ng/μl vs. 4.90 ± 0.40 ng/μl, P < 0.001). Additionally, a significant reduction has been found in transcription level of protamine 1 (25.49 ± 0.31 vs. 23.94 ± 0.40, P < 0.001) and protamine 2 (28.27 ± 0.39 vs. 23.45 ± 0.30, P < 0.001) in heavy smokers. A downregulation has been found in the transcription level of protamine 1 and protamine 2 with a fold change of 0.497 and 0.047, respectively. A significant increase has been shown in the level of DNA fragmentation and chromatin non-condensation in heavy smokers compared to non-smokers (P < 0.001). On the other hand, a significant positive correlation has been found between sperm chromatin non-condensation, sperm DNA fragmentation, transcription level of protamine 1, transcription level of protamine 2, and global DNA methylation status (r = 0.304, P < 0.001; r = 0.399, P < 0.001; r = 0.216, P = 0.003; r = 0.494, P < 0.001, respectively). Conclusion Tobacco cigarette smoking has a potential influence on the global DNA methylation and the transcription level of protamine genes in human spermatozoa, and consequently, affect negatively on the semen parameters.

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