Variation of sperm head shape and tail length in a species of Australian hydromyine rodent: the spinifex hopping mouse, Notomys alexis

2006 ◽  
Vol 18 (7) ◽  
pp. 797 ◽  
Author(s):  
M. Bauer ◽  
W. G. Breed
Keyword(s):  
Tail Length ◽  
Sperm Head ◽  
Filamentous Actin ◽  
Head Shape ◽  
Long Tail ◽  
Sperm Tail ◽  
Total Length ◽  
Murid Rodents ◽  
Species Specific ◽  
High Degree

In Australia, there are around 60 species of murid rodents that occur in the subfamily Hydromyinae, most of which produce highly complex, monomorphic, spermatozoa in which the head has an apical hook together with two ventral processes containing filamentous actin and a long tail of species-specific length. One of the few exceptions to this is the spinifex hopping mouse, Notomys alexis, whose spermatozoa have previously been shown to have pleiomorphic heads. In this study, the structural organisation of the sperm head has been investigated in more detail and the variability in length of the midpiece and total length of the sperm tail has been determined for this species. The findings confirm that pleiomorphic sperm heads are invariably present in these animals and that this variability is associated with that of the nucleus, although nuclear vacuoles were not evident. The total length of the sperm tail, as well as that of the midpiece, was also highly variable both within, as well as between, individual animals. The reason(s) for this high degree of variability in sperm morphology is not known but it may relate to a relaxation of the genetic control of sperm form owing to depressed levels of inter-male sperm competition.

Evolution of the Spermatozoon in Australasian Rodents

1997 ◽  
Vol 45 (5) ◽  
pp. 459 ◽  
Author(s):  
W. G. Breed
Keyword(s):  
Sperm Head ◽  
Anterior Region ◽  
Concave Surface ◽  
Evolutionary Trends ◽  
Filamentous Actin ◽  
Head Shape ◽  
Structural Organisation ◽  
Murid Rodents ◽  
Mammalian Spermatozoon

The head of the spermatozoon in eutherian mammals contains a nucleus, acrosomal cap and cytoskeleton. It is generally spatulate, paddle-shaped or pear-shaped, but in most murid rodents it is hook-shaped with the anterior region of the nucleus surrounded by an elaborate acrosome and an extension of the subacrosomal cytoskeleton as a perforatorium. This type of spermatozoon is present in Australasian Rattus, together with several other New Guinean genera. However, in most Australasian hydromyine rodents a far greater complexity of structural organisation of the sperm head has evolved in which two further elaborate processes extend from its upper concave surface. These processes contain a huge extension of the cytoskeleton within which filamentous actin is present. By contrast, the form of the sperm head in a few species of Pseudomys, Notomys and Solomys is highly divergent and is either truncated, spatulate or pear- shaped. The evolutionary trends of change in sperm head shape are discussed and it is suggested that the falciform sperm head with the two extra processes in most of the hydromyine rodents is one of the most morphologically complex sperm head types to have evolved in eutherian mammals; it contains a far more extensive development of the cytoskeleton than that of any other mammalian spermatozoon.

scholarly journals Greater sperm complexity in the Australasian old endemic rodents (Tribe: Hydromyini) is associated with increased levels of inter-male sperm competition

2017 ◽  
Vol 29 (5) ◽  
pp. 921 ◽  
Author(s):  
Hanna J. McLennan ◽  
Stefan Lüpold ◽  
Pete Smissen ◽  
Kevin C. Rowe ◽  
William G. Breed
Keyword(s):  
Sperm Competition ◽  
Sperm Morphology ◽  
Tail Length ◽  
Sperm Head ◽  
Sperm Tail ◽  
Apical Hook ◽  
Sexually Selected Traits ◽  
Male Sperm ◽  
Murid Rodents ◽  
Selected Traits

Spermatozoa exhibit considerable interspecies morphological variation across mammals, especially among murid rodents. In Australasia, most murids in the tribe Hydromyini have a spermatozoon with a highly complex head exhibiting an apical hook, characteristic of most murids, and two projections that extend from its upper concave surface, the ventral processes. In the present study we performed a phylogenetically controlled comparison of sperm morphology across 45 species of hydromyine rodents to test the hypothesis that the length and angle of both the apical hook and ventral processes, as well as the length of the sperm tail, increase with relative testes mass as a proxy for differences in levels of inter-male sperm competition. Although both sperm head protrusions exhibited considerable variation in their length and angle across species, only the angles increased significantly in relation to relative testes mass. Further, the length of the sperm flagellum was positively associated with relative testes mass. These results suggest that, in hydromyine rodents, the angle of the apical hook and ventral processes of the sperm head, as well as the sperm tail length, are likely to be sexually selected traits. The possible functional significance of these findings is briefly discussed.

scholarly journals The effects of inbreeding on sperm morphometry of captive-bred endangered mammals

2017 ◽  
Vol 95 (8) ◽  
pp. 599-606 ◽  
Author(s):  
M. Lawrence ◽  
G. Mastromonaco ◽  
K. Goodrowe ◽  
R.M. Santymire ◽  
W. Waddell ◽  
...  
Keyword(s):  
Captive Breeding ◽  
Negative Relationship ◽  
Tail Length ◽  
Poor Quality ◽  
Sperm Head ◽  
Head Width ◽  
Canis Rufus ◽  
Sperm Tail ◽  
Sperm Morphometry ◽  
Red Wolves

Captive breeding is used for the conservation of endangered species, but inbreeding can result when a small number of founders are used to establish populations. Inbreeding can reduce the proportion of normal sperm in an ejaculate, but may also have effects on sperm size and shape (morphometry). We investigated the effects of inbreeding on sperm morphometry of black-footed ferrets (Mustela nigripes (Audubon and Bachman, 1851)) and red wolves (Canis rufus Audubon and Bachman, 1851) from captive breeding programs to determine if more inbred males produced sperm of poor quality (bulky head, small midpiece, short tail). We measured sperm head length, head width, midpiece length, midpiece width, and tail length on 10 sperm from each male of both species. A negative relationship between variation in sperm tail length and inbreeding coefficient (f) was found in black-footed ferret, suggesting that more inbred individuals will have reduced genetic and phenotypic variation. Analyses indicated a negative relationship between sperm head width and f and a positive relationship between sperm tail length and f in red wolf, suggesting that more inbred male red wolves could have faster sperm. These results indicate that inbreeding affects functionally important aspects of sperm morphometry, but that these effects may not be entirely negative.

A mutation study of sperm head shape and motility in the mouse: lessons for the clinic

Andrology ◽  
2014 ◽  
Vol 3 (2) ◽  
pp. 174-202 ◽  
Author(s):  
P. de Boer ◽  
M. de Vries ◽  
L. Ramos
Keyword(s):  
Sperm Head ◽  
Head Shape

scholarly journals A species-specific nucleosomal signature defines a periodic distribution of amino acids in proteins

Open Biology ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 140218 ◽  
Author(s):  
Luis Quintales ◽  
Ignacio Soriano ◽  
Enrique Vázquez ◽  
Mónica Segurado ◽  
Francisco Antequera
Keyword(s):  
Amino Acids ◽  
Protein Composition ◽  
Open Reading Frames ◽  
Yeast Genome ◽  
Relative Distribution ◽  
Periodic Distribution ◽  
Wide Range ◽  
Average Distribution ◽  
Species Specific ◽  
High Degree

Nucleosomes are the basic structural units of chromatin. Most of the yeast genome is organized in a pattern of positioned nucleosomes that is stably maintained under a wide range of physiological conditions. In this work, we have searched for sequence determinants associated with positioned nucleosomes in four species of fission and budding yeasts. We show that mononucleosomal DNA follows a highly structured base composition pattern, which differs among species despite the high degree of histone conservation. These nucleosomal signatures are present in transcribed and non-transcribed regions across the genome. In the case of open reading frames, they correctly predict the relative distribution of codons on mononucleosomal DNA, and they also determine a periodicity in the average distribution of amino acids along the proteins. These results establish a direct and species-specific connection between the position of each codon around the histone octamer and protein composition.

Taxonomic status of male salamanders of the Ambystoma jeffersonianum complex from an Ontario population, with the first record of the Jefferson salamander, A. jeffersonianum (Green), from Canada

1976 ◽  
Vol 54 (8) ◽  
pp. 1270-1276 ◽  
Author(s):  
Wayne F. Weller ◽  
W. Gary Sprules
Keyword(s):  
Diploid Species ◽  
Taxonomic Status ◽  
Tail Length ◽  
First Record ◽  
Total Length ◽  
Ambystoma Jeffersonianum ◽  
Morphological Criteria ◽  
G Ratio ◽  
Jefferson Salamander

Nine morphological criteria were used to determine the taxonomic status of the male salamanders of the Ambystoma jeffersonianum complex from a population near Streetsville, Toronto Township, Peel County, Ontario: (a) snout–vent length; (b) ratio of tail length to snout–vent length; (c) internarial width; (d) extent of separation or overlap of the toes of adpressed limbs; (e) total length; (f) ratio of tail length to total length; (g) ratio of internarial width to snout–vent length; (h) colouration of dorsal, lateral, and ventral body surfaces; and, (i) extent and distribution of the bluish spotting. The results indicate that all of these males resemble A. jeffersonianum or A. platineum rather than A. latérale. Since A. platineum males occur very rarely in nature, these Streetsville individuals are logically assigned to A. jeffersonianum. This represents the first record of this species from Canada. Based upon this new distributional datum of A. jeffersonianum and of the two Diploid species from the literature, we suggest that these triploid species may have originated in post-Wisconsin times and subsequently dispersed northward.

scholarly journals The Role of Plasticity and Adaptation in the Incipient Speciation of a Fire Salamander Population

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 875
Author(s):  
Joana Sabino-Pinto ◽  
Daniel J. Goedbloed ◽  
Eugenia Sanchez ◽  
Till Czypionka ◽  
Arne W. Nolte ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Local Adaptation ◽  
Habitat Preferences ◽  
Genetic Change ◽  
Incipient Speciation ◽  
Expression Of Genes ◽  
Species Specific ◽  
Reciprocal Transfer ◽  
High Degree

Phenotypic plasticity and local adaptation via genetic change are two major mechanisms of response to dynamic environmental conditions. These mechanisms are not mutually exclusive, since genetic change can establish similar phenotypes to plasticity. This connection between both mechanisms raises the question of how much of the variation observed between species or populations is plastic and how much of it is genetic. In this study, we used a structured population of fire salamanders (Salamandra salamandra), in which two subpopulations differ in terms of physiology, genetics, mate-, and habitat preferences. Our goal was to identify candidate genes for differential habitat adaptation in this system, and to explore the degree of plasticity compared to local adaptation. We therefore performed a reciprocal transfer experiment of stream- and pond-originated salamander larvae and analyzed changes in morphology and transcriptomic profile (using species-specific microarrays). We observed that stream- and pond-originated individuals diverge in morphology and gene expression. For instance, pond-originated larvae have larger gills, likely to cope with oxygen-poor ponds. When transferred to streams, pond-originated larvae showed a high degree of plasticity, resembling the morphology and gene expression of stream-originated larvae (reversion); however the same was not found for stream-originated larvae when transferred to ponds, where the expression of genes related to reduction-oxidation processes was increased, possibly to cope with environmental stress. The lack of symmetrical responses between transplanted animals highlights the fact that the adaptations are not fully plastic and that some level of local adaptation has already occurred in this population. This study illuminates the process by which phenotypic plasticity allows local adaptation to new environments and its potential role in the pathway of incipient speciation.

scholarly journals PSXIII-4 Species feature of morphometric parameters in poultry semen

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 374-375
Author(s):  
Vugar A Bagirov ◽  
Anastasia N Vetokh ◽  
Mikhail A Zhilinsky ◽  
Hanum V Ashraf ◽  
Evgeniya K Tomgorova ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Guinea Fowl ◽  
Morphometric Parameters ◽  
Quality Analysis ◽  
Interspecific Difference ◽  
Head Shape ◽  
Total Length ◽  
Study Results ◽  
Sperm Morphometry ◽  
Parameters Analysis

Abstract The aim of the research was to study the specific features of morphometric parameters in rooster and guinea fowl spermatozoa. Thirty ejaculate samples from each species were investigated. A macroscopic assessment of the ejaculates obtained was carried out by volume, color and consistency. Microscopic parameters were studied using computerized sperm quality analysis systems. Diff-Quick set was used for staining sperm. Visualization of fixed preparations was performed using a Nikon Eclipse Ni-U microscope and a Nikon DS-Qi2 camera. Measurement of morphometric parameters was carried out in the program NIS-Elements BR 4.30. Evaluation of sperm morphometry was carried out according to the following indicators: total length of spermatozoa, length of head and tail, perimeter and area, head shape in indexes of ellipticity and elongation. The SPSS v.15.0 package was used for statistical analysis. To assess the statistical differences in the distributions of spermatozoa, the χ2-test was used. ANOVA was conducted to determine the effect of species. Roosters surpassed guinea fowls in ejaculate volume by 83.3% (P < 0.001). Statistically significant differences were not established for sperm activity between species. The content of motile spermatozoa in the roosters ejaculate was 92.4 ± 5.3%, in guinea fowls - 88.7 ± 6.54%. The results of the morphometric parameters analysis showed that they have a specific feature. The total length of rooster spermatozoa was 90 ± 2.6 μm, which is 8 μm more than that in guinea fowl (P < 0.05). The length of the sperm head in roosters was 2 μm longer than that in guinea fowls (P < 0.05). The interspecific difference across the perimeters and width of the head was not statistically significant. Rooster ejaculates differed relative homogeneity compared to guinea fowl. The study results showed that morphometric parameters of poultry sperm have a specific feature. Supported by the RSF (16-16-04104).

scholarly journals Variation in selection constraints on teleost TLRs with emphasis on their repertoire in the Walking catfish, Clarias batrachus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Manisha Priyam ◽  
Sanjay K. Gupta ◽  
Biplab Sarkar ◽  
T. R. Sharma ◽  
A. Pattanayak
Keyword(s):  
Phylogenetic Analysis ◽  
Positive Selection ◽  
Strong Evidence ◽  
Selection Pressure ◽  
Arms Race ◽  
Clarias Batrachus ◽  
Toll Like Receptors ◽  
Specific Variation ◽  
Species Specific ◽  
High Degree

AbstractThe high degree of conservation of toll-like receptors (TLRs), and yet their subtle variations for better adaptation of species in the host–pathogen arms race make them worthy candidates for understanding evolution. We have attempted to track the trend of TLR evolution in the most diverse vertebrate group—teleosts, where Clarias batrachus was given emphasis, considering its traits for terrestrial adaptation. Eleven C. batrachus TLRs (TLR1, 2, 3, 5, 7, 8 9, 13, 22, 25, 26) were identified in this study which clustered in proximity to its Siluriformes relative orthologues in the phylogenetic analysis of 228 TLRs from 25 teleosts. Ten TLRs (TLR1, 2, 3, 5, 7, 8 9, 13, 21, 22) with at least 15 member orthologues for each alignment were processed for selection pressure and coevolutionary analysis. TLR1, 7, 8 and 9 were found to be under positive selection in the alignment-wide test. TLR1 also showed maximum episodic diversification in its clades while the teleost group Eupercaria showed the maximum divergence in their TLR repertoire. Episodic diversification was evident in C. batrachus TLR1 and 7 alignments. These results present a strong evidence of a divergent TLR repertoire in teleosts which may be contributing towards species-specific variation in TLR functions.

Spermatozoa of the giant octopus of the North Pacific Octopus dofleini martini

1970 ◽  
Vol 175 (1038) ◽  
pp. 63-68 ◽  
Keyword(s):  
Carbohydrate Metabolism ◽  
North Pacific ◽  
Sperm Head ◽  
Glycolytic Pathway ◽  
Striking Feature ◽  
Total Length ◽  
The North ◽  
Condensed Nucleus ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The North Pacific

Spermatozoa of the giant octopus, as obtained from ruptured metre-long spermatophores, are only feebly motile. The total length of a spermatozoon is 1/2 mm, most of it due to the tail. The sperm-head, slim and oblong, is composed of a highly condensed nucleus and a cork-screw shaped acrosome. A striking feature, which distinguishes octopus spermatozoa from those of mammals, is the presence of a large amount of glycogen, concentrated mainly around the sperm-head. This, together with the occurrence of high phosphorylase and phosphoghlcomutase activity, indicates that glycogenolysis represents a pathway of carbohydrate metabolism in octopus spermatozoa. Both glucose-6-phosphate isomerase and glucose-6-phosphate dehydrogenase were demonstrated in extracts of prepared sperm- homogenates, which suggests that octopus spermatozoa may be capable of metabolizing glucose-6-phosphate along the oxidative as well as the glycolytic pathway.

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