Nuclear morphologies: their diversity and functional relevance

Chromosoma, Journal Year: 2016, Volume and Issue: 126(2), P. 195 - 212

Published: Sept. 8, 2016

Studies of chromosome and genome biology often focus on condensed chromatin in the form chromosomes neglect non-dividing cells. Even when interphase nuclei are considered, they then treated as interchangeable round objects. However, different cell types can have very nuclear shapes, these shapes impacts cellular function; indeed, many pathologies linked with alterations to shape. In this review, we describe some morphologies beyond spherical ovoid. Many leukocytes immune system lobed nuclei, which aid their flexibility migration; smooth muscle cells a spindle shaped nucleus, must deform during contractions; spermatozoa highly adopt varied potentially associated swimming efficiency. Nuclei not passive passengers within cell. There clear effects shape transcriptional activity Recent work has shown that regulation gene expression be influenced by morphology, drastically remodel differentiation. The link between nucleoskeleton cytoskeleton at envelope provides mechanism for transmission mechanical forces into directly affecting compaction organisation.

Language: Английский

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Sex chromosome inversions enforce reproductive isolation across an avian hybrid zone

Molecular Ecology, Journal Year: 2018, Volume and Issue: 28(6), P. 1246 - 1262

Published: Sept. 19, 2018

Abstract Across hybrid zones, the sex chromosomes are often more strongly differentiated than autosomes. This is regularly attributed to greater frequency of reproductive incompatibilities accumulating on and their exposure in heterogametic sex. Working within an avian zone, we explore possibility that chromosome inversions differentially accumulate Z compared autosomes thereby contribute differentiation. We analyse northern Australian zone between two subspecies long‐tailed finch ( Poephila acuticauda ), first described based differences bill colour, using reduced‐representation genomic sequencing for 293 individuals over a 1,530‐km transect. Autosomal differentiation minimal. In contrast, 75% highly shows steep cline, which displaced 350 km west cline colour. Differentiation associated with or putative chromosomal inversions, each predominating one subspecies. If reduce recombination incompatibilities, they selectively favoured should therefore zones. argue this predisposes chromosome. One region affecting colour Z, but main candidates 8. displacement centres suggest has not contributed inversion accumulation. Based width, however, both isolation established pair

Language: Английский

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Experimental heatwaves negatively impact sperm quality in the zebra finch

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2018, Volume and Issue: 285(1871), P. 20172547 - 20172547

Published: Jan. 17, 2018

For sexually reproducing species, functionally competent sperm are critical to reproduction. While high atmospheric temperatures known influence the timing of breeding, incubation and reproductive success in birds, effect temperature on quality remains largely unexplored. Here, we experimentally investigated impact ecologically relevant extreme cloacal morphology motility zebra finches Taeniopygia guttata . We periodically sampled males exposed 30°C or 40°C daily for 14 consecutive days. Following a 12-day (23°C) recovery period, birds were again heat, but under alternate treatment (e.g. initially 30°C). Elevated led an increase reduction proportion with normal morphology; these effects most notable conditions, influenced by duration heat exposure prior temperature. Our findings highlight potential role determining male fertility perhaps also constraining avian breeding. Given increased frequency heatwaves warming world, our results suggest need further work climatic influences fertility.

Language: Английский

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Sperm head morphology is associated with sperm swimming speed: A comparative study of songbirds using electron microscopy

Evolution, Journal Year: 2018, Volume and Issue: 72(9), P. 1918 - 1932

Published: July 17, 2018

Sperm exhibit extraordinary levels of morphological diversification across the animal kingdom. In songbirds, sperm have a helically shaped head incorporating distinct acrosomal membrane or "helical keel," form and extent which varies species. The functional significance this helical shape, however, remains unknown. Using scanning electron microscopy, we quantified inter‐ intraspecific variation in morphology 36 songbird species (Passeriformes: Passerida). phylogenetic comparative methods, investigated relationship between both swimming speed frequency extra‐pair young (EPY). We found that whose had relatively more pronounced (i.e., long acrosome, short nucleus, wide membrane, waveform along "core") faster‐swimming sperm. no evidence interspecific EPY, although did find among‐ within‐male traits were negatively correlated with EPY. Applying principles fluid mechanics, discuss how may influence speed, suggest further studies considering aspects beyond length are needed to improve our understanding structure‐function relationships.

Language: Английский

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Mitonuclear interactions impact aerobic metabolism in hybrids and may explain mitonuclear discordance in young, naturally hybridizing bird lineages

Molecular Ecology, Journal Year: 2024, Volume and Issue: 33(12)

Published: May 10, 2024

Abstract Understanding genetic incompatibilities and introgression between incipient species are major goals in evolutionary biology. Mitochondrial genes evolve rapidly exist dense gene networks with coevolved nuclear genes, suggesting that mitochondrial respiration may be particularly susceptible to disruption hybrid organisms. Mitonuclear interactions have been demonstrated contribute dysfunction deeply divergent taxa crossed the laboratory, but there few empirical examples of mitonuclear younger lineages naturally hybridize. Here, we use controlled crosses high‐resolution respirometry provide first experimental evidence a bird inter‐lineage impact aerobic metabolism. Specifically, capacity two mitodiscordant backcrosses (with mismatched combinations) differs from one another, although they do not differ significantly parental groups or mitoconcordant as would expect disruptions. In wild zone these subspecies, cline centre is shifted west centre, which consistent direction our results. Our results therefore demonstrate asymmetric cellular help explain geographic discordance genomes observed wild.

Language: Английский

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Species-level divergences in multiple functional traits between the two endemic subspecies of Blue Chaffinches Fringilla teydea in Canary Islands

BMC Zoology, Journal Year: 2016, Volume and Issue: 1(1)

Published: Aug. 18, 2016

One of the biggest challenges in avian taxonomy is delimitation allopatric species because their reproductive incompatibility cannot be directly studied wild. Instead, has to inferred from multiple, divergent character sets that indicate a low likelihood populations amalgamating upon secondary contact. A set quantitative criteria for been developed taxonomy. Here, we report broad multi-trait comparison two insular subspecies Blue Chaffinch Fringilla teydea, endemic pine forests Tenerife (ssp. teydea) and Gran Canaria polatzeki) Canary Islands. We found taxa were reciprocally monophyletic whole mitogenomes Z chromosome introns. The genetic distance indicates around 1 Mya evolution. There diagnostic differences body morphometrics, song plumage reflectance spectra, whose combined divergence score (=11) exceeds threshold level (=7) by Tobias et al. (Ibis 152:724–746, 2010). Moreover, marked sperm lengths with little range overlap. Relatively long intra- intermale CV compared other passerines suggest mating system high levels competition (extrapair paternity) these taxa. large divergences multiple functional traits qualify rank, i.e., (Fringilla polatzeki). encourage wider use might signal at postcopulatory prezygotic stage, especially competition.

Language: Английский

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Experimentally testing mate preference in an avian system with unidirectional bill color introgression

Ecology and Evolution, Journal Year: 2023, Volume and Issue: 13(2)

Published: Feb. 1, 2023

Mating behavior can play a key role in speciation by inhibiting or facilitating gene flow between closely related taxa. Hybrid zones facilitate direct examination of mating and the traits involved establishing species barriers. The long-tailed finch (

Language: Английский

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Optimal analysis conditions for sperm motility parameters with a CASA system in a passerine bird, Passer montanus

Avian Research, Journal Year: 2019, Volume and Issue: 10(1)

Published: Sept. 10, 2019

Abstract Background Sperm motility parameters, which can be measured objectively and repeatedly by a computer-assisted sperm analysis (CASA) system, are important indicators of quality. However, the parameters assessed CASA system affected various factors, including instrument components settings, preparation or procedures. To date, no standardized protocol is available that would permit to assess kinetic characteristics in passerine birds this lack precludes any comparison swimming ability quality across species. Methods In study, we chose Tree Sparrow ( Passer montanus ) as object evaluate motility, velocity movement trajectory, at different time, temperatures pH using WLJY-9000 system. Results remained statistically unchanged 1‒9 min. Progressive was similar 38 °C 40 °C, but greater percentage slow progressive detected compared 42 °C. Additionally, lower immotility higher than and/or (close body temperature Sparrow). The percentages rapid sperm, immotile were 7.0, 7.5 8.0 with exception 7.0 7.5. addition, slower worse trajectory found 6.0 9.0 those 8.0, 7.0. Conclusions Our study indicates ideal conditions for assessment obtained between 1 9 min after dilution, an environment (40 °C) around 7.5‒8.0. results provide reference evaluation birds.

Language: Английский

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Evaluating evidence of mitonuclear incompatibilities with the sex chromosomes in an avian hybrid zone

Evolution, Journal Year: 2021, Volume and Issue: 75(6), P. 1395 - 1414

Published: April 28, 2021

The exploration of hybrid zones and the intergenomic conflicts exposed through hybridization provide windows into processes divergence speciation. Sex chromosomes mitonuclear incompatibilities have strong associations with genetics dysfunction. In ZW sex-determining systems, maternal co-inheritance mitochondrial W immediately exposes between these contributions one species Z chromosome another. We analyze admixture in long-tailed finch (Poephila acuticauda) Australia, where hybridizing subspecies differ prominently genotype bill color, yet respective centers geographic for two traits are offset by 350 km. report well-defined clades that diverged ∼0.5 million years ago. Mitochondrial contact is geographically co-located within a zone displaced from color nearly 400 Consistent Haldane's rule expectations, females significantly less likely than males to carry an admixed or mismatched Z-mitochondrial genotypes. Furthermore, there fewer expected mismatches paternal backcross males. Results suggest potential mitonuclear/sex emergence reproductive isolation this system.

Language: Английский

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New Insights Into Sperm Ultrastructure Through Enhanced Scanning Electron Microscopy

Frontiers in Cell and Developmental Biology, Journal Year: 2021, Volume and Issue: 9

Published: April 22, 2021

The analysis of spermatozoa morphology is fundamental to understand male fertility and the etiology infertility. Traditionally scanning electron microscopy (SEM) has been used define surface topology. Recently, however, it become a critical tool for three-dimensional internal cellular ultrastructure. Modern SEM provides nanometer-scale resolution, but meaningfulness such information proportional quality sample preservation. In this study, we demonstrate that sperm quickly robustly adhere gold-coated surfaces. Leveraging property, developed three step-by-step protocols fulfilling different needs imaging: chemically fixed monolayers examination external morphology, two high-pressure freezing-based fast full cell focused ion-beam tomography. These analyses allow previously unappreciated insights into mouse ultrastructure, including identification novel structures within fibrous sheath domain-specific interactions between plasma membrane exosome-like structures.

Language: Английский

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