Scrotal insulation and its relationship to abnormal morphology, chromatin protamination and nuclear shape of spermatozoa in Holstein-Friesian and Belgian Blue bulls

Rahman, Bahanur; Vandaele, Leen; Rijsselaere, Tom; Maes, Dominiek; Hoogewijs, Maarten; Frijters, A.; Noordman, Jakomien; Granados, Ana; Dernelle, Eric; Shamsuddin, M.; Parrish, J.J.; Soom, Ann Van

doi:10.1016/j.theriogenology.2011.05.031

Cited by 108 publications

(102 citation statements)

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“…Increased testicular temperature (,28C) during the spermatogenic cycle, especially during the spermiogenic and meiotic stages of germ cell development, even for a short period of time (i.e. 48 h) affects sperm motility, morphology, plasma membrane integrity, chromatin protamination and nuclear shape (Rahman et al 2011). Similarly, after collection of ejaculate, maintenance of the ejaculate temperature close to testicular temperature (,328C) is important for the maintenance of proper sperm functional properties.…”

Section: Discussionmentioning

confidence: 99%

“…The parameter settings were as described in previous studies (Rahman et al 2011(Rahman et al , 2012: frame rate 60 Hz; number of frames 30; minimum contrast 20; minimum cell size 10 pixels; nonmotile head size 5 pixels; non-motile head intensity 20; medium path velocity (VAP) cut-off 50 mm s À1 ; straightness (STR) cut-off 70%; low VAP cut-off 30 mm s À1 ; and low straight line velocity (VSL) cut-off 15 mm s À1 . Using the play-back facility, preliminary trials were performed to evaluate whether the spermatozoa were correctly identified.…”

Section: Computer-assisted Sperm Analysismentioning

confidence: 99%

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Bovine spermatozoa react to in vitro heat stress by activating the mitogen-activated protein kinase 14 signalling pathway

Rahman

Vandaele²,

Rijsselaere

et al. 2014

Reprod. Fertil. Dev.

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Abstract. Heat stress has long been recognised as a cause of subfertility in farm animals. The objectives of the present study were to elucidate the effect of heat stress on sperm function and involvement of the mitogen-activated protein kinase (MAPK) 14 signalling pathway. Spermatozoa incubated for 4 h at a physiological temperature (38.58C) exhibited significantly (P , 0.05) reduced motility, plasma membrane integrity and mitochondrial potential compared with nonincubated spermatozoa; the reductions in these parameters were more severe following incubation at a hyperthermic (418C) temperature (P , 0.01). Percentages of fertilisation and embryo development were highly affected in spermatozoa incubated at 418C compared with non-incubated spermatozoa (P , 0.01). Similarly, embryo quality was adversely affected by sperm incubation at 418C, as indicated by a higher apoptotic cell ratio in Day 7 blastocysts compared with that in the non-incubated control group (14.6% vs 6.7%, respectively; P , 0.01). Using SB203580 (10 mg mL À1 ), a specific inhibitor of the p38 MAPK pathway, during sperm hyperthermia reduced MAPK14 activation (24.9% vs 35.6%), increased sperm motility (45.8% vs 26.5%) and reduced DNA fragmentation (16.9% vs 23.4%) compared with the untreated control group, but did not improve subsequent fertilisation and embryo development. In conclusion, heat stress significantly affects the potential of spermatozoa to penetrate oocytes, as well as subsequent embryo development and quality. Notably, the data show that the MAPK14 signalling pathway is largely involved in heat-induced sperm damage. However, further research is needed to elucidate other signalling pathways possibly involved in heat-induced sperm damage.Additional keywords: functional parameters, mitogen-activated protein kinase 14 phosphorylation, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling.

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Section: Discussionmentioning

confidence: 99%

Section: Computer-assisted Sperm Analysismentioning

confidence: 99%

Bovine spermatozoa react to in vitro heat stress by activating the mitogen-activated protein kinase 14 signalling pathway

Rahman

Vandaele²,

Rijsselaere

et al. 2014

Reprod. Fertil. Dev.

Self Cite

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“…Studies of the hydrodynamic efficiency of sperm from a range of different species have shown that sperm with morphological abnormalities are poorer swimmers, such as in humans (Katz et al 1982; Gillies et al 2009) and bulls (Ostermeier et al 2001). Subsequent studies in cattle demonstrated that sperm motility varies between cattle breeds, and also varies depending on the temperature at which the sperm were developing (Rahman et al 2011). …”

Section: Spermatozoamentioning

confidence: 99%

Nuclear morphologies: their diversity and functional relevance

2016

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

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“…Exposure of bulls to heat stress during spermatogenesis can affect protamination of their spermatozoa. The lack of chromatin protamination is the most pertinent consequence of heat stress, together with subtle changes in sperm head shape (Rahman et al 2011). In mice, it has been examined whether stressors imposed upon male mice can be transferred to future generations (so-called 'transgenerational epigenetic inheritance'), which implicates sperm as a mechanism of transmitting heritable non-DNA based information from one generation to the next (Pembrey 2010).…”

mentioning

confidence: 99%