scholarly journals Successful mating and hybridisation in two closely related flatworm species despite significant differences in reproductive morphology and behaviour

2019 ◽  
Author(s):  
Pragya Singh ◽  
Daniel Ballmer ◽  
Max Laubscher ◽  
Lukas Schärer
Keyword(s):  
Parental Species ◽  
Mating Behaviour ◽  
Reproductive Traits ◽  
F1 Hybrids ◽  
Reproductive Barriers ◽  
Free Living ◽  
Mating Rate ◽  
Successful Mating ◽  
Gradual Process ◽  
Morphological Differences

AbstractSpeciation is usually a gradual process, in which reproductive barriers between two species accumulate over time. Reproductive traits, like genital morphology and mating behaviour, are some of the fastest diverging characters and can serve as reproductive barriers. The free-living flatworm Macrostomum lignano, an established model for studying sex in hermaphrodites, and its congener M. janickei are closely related, but differ substantially in their male intromittent organ (stylet) morphology. Here, we examine whether these morphological differences are accompanied by differences in behavioural traits, and whether these could represent barriers to successful mating and hybridization between the two species. Our data shows that the two species differ in many aspects of their mating behaviour, with M. janickei having a five-fold longer copulation duration, copulating less frequently, and having a longer and more delayed suck behaviour (a postcopulatory behaviour likely involved in sexual conflict). Interestingly, and despite these significant morphological and behavioural differences, the two species mate readily with each other in heterospecific pairings, often showing behaviours of intermediate duration. Although both species have similar fecundity in conspecific pairings, the heterospecific pairings revealed clear postmating barriers, as only few heterospecific pairings produced F1 hybrids. These hybrids had a stylet morphology that was intermediate between that of the parental species, and they could successfully backcross to both parental species. Finally, in a mate choice experiment we tested if the worms preferentially mated with conspecifics over heterospecifics, since such a preference could represent a premating barrier. Interestingly, the experiment showed that the nearly two-fold higher mating rate of M. lignano caused it to mate more with conspecifics, leading to assortative mating, while M. janickei ended up mating more with heterospecifics. Thus, while the two species can hybridize, the mating rate differences could possibly lead to higher fitness costs for M. janickei compared to M. lignano.

scholarly journals Maternal inheritance of F1 hybrid morphology and colony shape in the coral genus Acropora

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6429 ◽  
Author(s):  
Hironobu Fukami ◽  
Kenji Iwao ◽  
Naoki H. Kumagai ◽  
Masaya Morita ◽  
Naoko Isomura
Keyword(s):  
Parental Species ◽  
Morphological Characters ◽  
F1 Hybrids ◽  
F1 Hybrid ◽  
Maternal Parent ◽  
Coral Genus ◽  
Molecular Features ◽  
Morphological Differences ◽  
Colony Shape

Background The coral genus Acropora contains more than 150 species with very high morphological diversity. This high diversity may have been caused by repeated hybridization via mass spawning. However, we have little information whether hybrids are formed in these corals. Identifying morphological differences between hybrids and their parental species would provide an opportunity to find wild hybrids in the field and to understand how colony shapes of Acropora have become highly diversified throughout evolutionary history. In the two morphologically distinctive coral species Acropora florida and A. intermedia in the Indo-Pacific, their gametes show high rates of bi-directional intercrossing in vitro, and thus these two species are ideal species to investigate the morphological traits of the hybrids. Methods We examined morphological characters of F1 hybrids from A. florida to A. intermedia, which were produced from in vitro crossing experiments. To compare morphological differences, we grew juveniles and mature colonies of reciprocal F1 hybrids (FLOint: A. florida eggs × A. intermedia sperm, and INTflo: A. intermedia eggs × A. florida sperm) and of the parental species (purebreds of A. intermedia and A. florida). We analyzed skeletal morphology such as colony size, branch length, and branching number, and compared them with those of a putative F1 hybrid between A. florida and A. intermedia found in the field. We also confirmed the molecular phylogenetic position of F1 hybrids, parental species, and a putative F1 hybrid using the mitochondrial non-coding region. Results Our morphological analysis revealed that branching number of the F1 hybrids was intermediate relative to the parental species. Moreover, the FLOint hybrids were morphologically more closely related to the maternal species A. florida, and the INTflo hybrids were to A. intermedia. Molecular data showed that A. florida and A. intermedia were clearly divided into two clades, and that F1 hybrids grouped in the clade based on their maternal parent. A very similar pattern to the INTflo hybrids was obtained for the putative F1 hybrid in nature. Discussion Our results revealed that F1 hybrids between two Indo-Pacific species A. florida and A. intermedia had intermediate morphology relative to their parent species but reflected the maternal parent more. Similarity to maternal species in hybrids is opposite to the Caribbean Acropora species that had more paternal morphological characters in hybrids. These results further suggest that some genetic factor in eggs is likely to affect determination of colony shape in the Indo-Pacific. At present, we have considered colonies with intermediate morphs between different species to be intra-specific morphological variation, but they may be real F1 hybrids. Indeed, a putative F1 hybrid represented similar morphological and molecular features to the F1 hybrids, and thus it is plausible to be attributed as a “real” F1 hybrid in nature.

scholarly journals Frequent origins of traumatic insemination involve convergent shifts in sperm and genital morphology

2021 ◽  
Author(s):  
Jeremias N. Brand ◽  
Luke J. Harmon ◽  
Lukas Schärer
Keyword(s):  
Morphological Changes ◽  
Mating Behaviour ◽  
Reproductive Traits ◽  
Control Mechanisms ◽  
Genital Morphology ◽  
Free Living ◽  
Sperm Donor ◽  
Male And Female ◽  
Evolutionary Origins ◽  
Female Reproductive Traits

AbstractTraumatic insemination is a mating behaviour during which the (sperm) donor uses a traumatic intromittent organ to inject an ejaculate through the epidermis of the (sperm) recipient, thereby frequently circumventing the female genitalia. Traumatic insemination occurs widely across animals, but the frequency of its evolution, the intermediate stages via which it originates, and the morphological changes that such shifts involve remain poorly understood. Based on observations in 145 species of the free-living flatworm genus Macrostomum, we identify at least nine independent evolutionary origins of traumatic insemination from reciprocal copulation, but no clear indication of reversals. These origins involve convergent shifts in multivariate morphospace of male and female reproductive traits, suggesting that traumatic insemination has a canalising effect on morphology. Signatures of male-female coevolution across the genus indicate that sexual selection and sexual conflict drive the evolution of traumatic insemination, because it allows donors to bypass postcopulatory control mechanisms of recipients.

scholarly journals Sequencing an F1 hybrid of Silurus asotus and S. meridionalis enabled the assembly of high-quality parental genomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weitao Chen ◽  
Ming Zou ◽  
Yuefei Li ◽  
Shuli Zhu ◽  
Xinhui Li ◽  
...  
Keyword(s):  
De Novo ◽  
Parental Species ◽  
F1 Hybrids ◽  
Pelteobagrus Fulvidraco ◽  
F1 Hybrid ◽  
Short Reads ◽  
Final Assembly ◽  
Genome Complexity ◽  
Hybrid Genome ◽  
Silurus Asotus

AbstractGenome complexity such as heterozygosity may heavily influence its de novo assembly. Sequencing somatic cells of the F1 hybrids harboring two sets of genetic materials from both of the paternal and maternal species may avoid alleles discrimination during assembly. However, the feasibility of this strategy needs further assessments. We sequenced and assembled the genome of an F1 hybrid between Silurus asotus and S. meridionalis using the SequelII platform and Hi-C scaffolding technologies. More than 300 Gb raw data were generated, and the final assembly obtained 2344 scaffolds composed of 3017 contigs. The N50 length of scaffolds and contigs was 28.55 Mb and 7.49 Mb, respectively. Based on the mapping results of short reads generated for the paternal and maternal species, each of the 29 chromosomes originating from S. asotus and S. meridionalis was recognized. We recovered nearly 94% and 96% of the total length of S. asotus and S. meridionalis. BUSCO assessments and mapping analyses suggested that both genomes had high completeness and accuracy. Further analyses demonstrated the high collinearity between S. asotus, S. meridionalis, and the related Pelteobagrus fulvidraco. Comparison of the two genomes with that assembled only using the short reads from non-hybrid parental species detected a small portion of sequences that may be incorrectly assigned to the different species. We supposed that at least part of these situations may have resulted from mitotic recombination. The strategy of sequencing the F1 hybrid genome can recover the vast majority of the parental genomes and may improve the assembly of complex genomes.

Acoustic Communication and Mating Behaviour in the Muellerianella Complex (Homoptera - Delphacidae)

Behaviour ◽  
1985 ◽  
Vol 94 (1-2) ◽  
pp. 183-201 ◽  
Author(s):  
S. Drosopoulos
Keyword(s):  
Mating Behavior ◽  
Acoustic Communication ◽  
Parental Species ◽  
Mating Behaviour ◽  
Interspecific Crosses ◽  
Bisexual Species ◽  
Duration Of Copulation ◽  
Isolating Mechanisms ◽  
Copulation Behavior ◽  
Biological Differences

AbstractSome data on acoustic communication and mating behavior of two biparentally reproducing species and the clonally reproducing pseudogamous "species" of the genus Muellerianella are reported. Although bioacoustic differences were found in the calling songs between the species, these did not prevent pairforming. Also, differences in mating behavior, such as pre-copulation behavior, courtship activities, frequency and duration of copulation were not sufficient to prevent successful hybridization between both the two biparentally reproducing species and between each of these two species and the pseudogamous "species". The data reported here are related to other biological differences reported previously. According to these data there is some evidence that differences in acoustic communication and mating behavior between the two species are established by ecological influences which in turn have established analogous physiological requirements. These differences are rather weak isolating mechanisms. Regarding the behavioral relation of the pseudogamous species with males of the two parental species it was found that these females behave exactly as the females of M. fairmairei with which they coexist in the field. In interspecific crosses mechanical barriers to copulation are more efficient than courtship differences. Finally it is assumed that pseudogamy is a strong isolation mechanism between the not yet fully genetically differentiated bisexual species of Muellerianella.

scholarly journals GENOME SIZE IN THREE SPECIES OF Glandularia AND THEIR HYBRIDS

2019 ◽  
Vol 30 (2) ◽  
pp. 47-54
Author(s):  
M.R. Ferrari ◽  
E.J. Greizerstein ◽  
L. Poggio
Keyword(s):  
Genome Size ◽  
Dna Content ◽  
High Frequency ◽  
Parental Species ◽  
The Other ◽  
F1 Hybrids ◽  
Homoeologous Pairing ◽  
The Relationship ◽  
Species Being ◽  
Homoeologous Chromosomes

In this work the relationship between genome size of Glandularia species and the meiotic configurations found in their hybrids are discussed. Glandularia incisa (Hook.) Tronc., growing in two localities of Corrientes and Córdoba provinces, Argentina, with different ecological conditions, showed inter-population variability of the 2C-value. The DNA content found in the Corrientes locality (2.41 pg) was higher than that obtained in the Córdoba locality (2.09 pg) which has more stressful environmental conditions than the former. These values are statistically different from those that were found in Glandularia pulchella (Sweet) Tronc. from Corrientes (1.43 pg) and in Glandularia perakii Cov. et Schn from Córdoba (1.47 pg). The DNA content of the diploid F1 hybrids, G. pulchella × G. incisa and G. perakii × G. incisa, differed statistically from the DNA content of the parental species, being intermediate between them. Differences in the frequency of pairing of homoeologous chromosomes were observed in the hybrids; these differences cannot be explained by differences in genome size since hybrids with similar DNA content differ significantly in their meiotic behavior. On the other hand, the differences in the DNA content between the parental species justify the presence of a high frequency of heteromorphic open and closed bivalents and univalents with different size in the hybrids. Key words: Intra-specific DNA content variability, homoeologous pairing, heteromorphic bivalents

scholarly journals A Unique Conjunction: Evidence for Gynogenesis Accompanying Haplodiploid Sex Determination in the Australian Ant Myrmecia impaternata Taylor

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Robert W. Taylor ◽  
Hirotami T. Imai ◽  
Eisuke Hasegawa ◽  
Colin D. Beaton
Keyword(s):  
Host Species ◽  
Related Species ◽  
Parental Species ◽  
Female Offspring ◽  
Hybrid Origin ◽  
Sperm Cells ◽  
Reproductive Systems ◽  
Free Living ◽  
Sperm Donor ◽  
Diploid Female

Myrmecia impaternata is an allodiploid all-female species of hybrid origin. Its parental taxa are confirmed here to be M. banksi and M. pilosula. We suggest that its queens produce diploid female offspring by gynogenetic parthenogenesis, a process which requires interaction between unreduced maternal oocytes and allospecific sperm cells obtained by copulation with another related species. We propose that impaternata queens almost certainly mate for this purpose with males reared in impaternata nests from eggs laid by impaternata females. Because sex in ants is determined by haplodiploidy (males haploid, females diploid), we posit that these males would in fact not be technically conspecific with the females in whose reproductive systems they developed, since they would each carry the haploid genome of one or other of the hybridic parental species. They would therefore be individually identical karyologically to males of either M. banksi or M. pilosula and appropriately allospecific to M. impaternata. We postulate that, unlike all other known gynogens, M. impaternata would have no need to maintain parasitic affiliation or sympatry with free-living sperm-donor host species. Its queens are arguably able to produce the required allospecific males by accessing their own genomes. M. impaternata apparently originated by instantaneous speciation when individuals of its parental species first successfully hybridized.

Revision of the genus Setosella (Bryozoa: Cheilostomata) with description of new species from deep-waters and submarine caves of the Mediterranean Sea

Zootaxa ◽  
2020 ◽  
Vol 4728 (4) ◽  
pp. 401-442 ◽  
Author(s):  
A. ROSSO ◽  
E. DI MARTINO ◽  
V. GEROVASILEIOU
Keyword(s):  
New Species ◽  
Southern Italy ◽  
Free Living ◽  
Deep Waters ◽  
Scanning Electron Microscopy Examination ◽  
Species Complexes ◽  
Morphological Differences ◽  
Three New Species ◽  
Submarine Caves ◽  
Microscopy Examination

The genus Setosella included to date six species. After revision, only four of these species were retained, i.e. S. vulnerata, S. cavernicola, S. folini and S. spiralis. The remaining two species were tentatively placed in Woodipora, W.? antilleana n. comb., and Andreella,  A.? fragilis n. comb. On the other hand, scanning electron microscopy examination of Mediterranean material, revealed the presence of three new species previously included in species complexes: S. cyclopensis n. sp. from the open-shelf, S. rossanae n. sp. from submarine caves, and S. alfioi n. sp. from deep-waters. The diagnosis of the genus was amended to include the occurrence of kenozooids in S. cyclopensis n. sp. and S. cavernicola, and of free-living ring-shaped and scorpioid colonies in S. folini and S. alfioi n. sp. All the seven species n           1ow in Setosella have present-day representatives; the geographic distribution of the genus 1sinian of southern Italy and insular Greece, with only three species occasionally and discontinuously reported. All species are able to produce numerous, subsequent intramural buds and morphological differences seem to be consistently associated with exploitation of particular habitats and substrata. 

Performance of purebred and crossbred rabbits in Australia: doe reproductive and pre-weaning litter traits

2002 ◽  
Vol 53 (9) ◽  
pp. 993 ◽  
Author(s):  
K. C. Prayaga ◽  
S. J. Eady
Keyword(s):  
Birth Weight ◽  
Reproductive Traits ◽  
Significant Negative Correlation ◽  
Average Birth Weight ◽  
Successful Mating ◽  
Litter Traits ◽  
Coefficients Of Variation ◽  
Parity Number ◽  
Breed Crosses ◽  
Foundation Stock

Data from a rabbit breeding experiment were analysed to compare the doe reproductive and pre-weaning litter performance of 3 breeds of rabbits, namely New Zealand White (N), Californian (C), and Flemish Giant (F), and their crosses CN (C × N) and FN (F × N). The foundation stock of 152 rabbits was collected from 26 different sources in New South Wales, Australia. Data on reproductive traits, doe age at first successful mating (DA), doe weight at first successful mating (DW) arising from 104 does, conception rate (CR) from 808 matings, and kindling interval (KI) from 325 records of 119 does were analysed. Overall means for reproductive traits DA, DW, CR, and KI were 21 weeks, 3.6 kg, 0.75, and 7.4 weeks, respectively. DA, CR, and KI did not differ significantly among different breeds and their crosses. DW of C does was found to be significantly lighter than all other breed crosses in the study. Month–year of mating significantly affected DA, DW, and CR (P < 0.01), and as the parity number increased, there was a significant (P < 0.01) decrease in KI. As age of the doe at mating increased there was a significant increase in DW (P < 0.01), CR (P < 0.05), and KI (P < 0.01). Data from 436 litters of 157 does were included in the analysis of pre-weaning litter traits. The overall means for the pre-weaning litter traits were: number born per litter (NB, 8.1), number born alive per litter (NBA, 6.9), number weaned per litter (NW, 3.3), total litter birth weight (TLBW, 453.7 g), live litter birth weight (LLBW, 397.1 g), litter weaning weight (LWW, 2.8 kg), and average birth weight of kits per litter (ABW, 58.1 g). Doe breed significantly affected NW (P < 0.05), TLBW (P <�0.01), LLBW (P < 0.05), LWW, and ABW (P < 0.01). N does and crossbred does (CN and FN) performed better than purebred F and C does for NW and LWW. A significant heterosis of 41.9% and 40.8% was observed in CN does for traits NW and LWW, respectively. ABW of F does was significantly higher than that of all other breed crosses in the study. Buck breed did not have any significant effect on any of the pre-weaning litter traits under study. Parity significantly affected NW (P < 0.05), TLBW (P < 0.01), LLBW (P < 0.05), and ABW (P < 0.01). First parity does produced litters with significantly lighter birth weights. The month–year of birth effect was significant for NW, LWW (P < 0.01), and ABW (P < 0.05).�The coefficients of variation for the doe reproductive traits and pre-weaning litter traits ranged between 12.1 and 59.5% and 16.1 and 93.3%, respectively. High phenotypic variances and coefficients of variation observed for traits NW and LWW indicate that good response could be realised through selection. Repeatability estimates for reproductive traits CR and KI were very low. Low to moderate repeatability estimates in the range 0.17–0.25 were observed for pre-weaning litter traits. Significant positive phenotypic correlations were observed between litter size and litter weight traits (0.30–0.97). A significant negative correlation was observed between ABW and NB (–0.56) and NBA (–0.36).

Pinguicula filifolia subsp. alba (Lentibulariaceae), a new subspecies with an extremely restricted distribution in Pinar del Río, Cuba

Phytotaxa ◽  
2014 ◽  
Vol 158 (1) ◽  
pp. 85
Author(s):  
Yoannis Domínguez ◽  
Cristina Mercedes Panfet Valdés ◽  
Vitor Fernandes Oliveira De Miranda
Keyword(s):  
Morphological Analysis ◽  
Reproductive Traits ◽  
Carnivorous Plant ◽  
Habitat Specificity ◽  
New Subspecies ◽  
Restricted Distribution ◽  
Seed Characters ◽  
Morphological Differences ◽  
Isla De La Juventud ◽  
Del Rio

The carnivorous plant Pinguicula filifolia occurs in western Cuba and shows a restricted distribution due to habitat specificity associated with poor wet soils. Its populations are distributed mainly in south Pinar del Río (Cuba) and in Isla de la Juventud. Plants from one isolated location in NW Pinar del Río shows morphological differences with respect to the rest of the known populations observed in nature. Subsequent detailed morphological analysis of specimens led to the description of Pinguicula filifolia subsp. alba as a new subspecies. It differs from the typical subspecies in several reproductive traits involving flower, fruit and seed characters and is so far known only from the type locality.

Molecular genetic evidence for allotetraploid hybrid speciation in the genus Crocus L. (Iridaceae)

Phytotaxa ◽  
2016 ◽  
Vol 258 (2) ◽  
pp. 121 ◽  
Author(s):  
ÁGNES MOSOLYGÓ-L ◽  
GÁBOR SRAMKÓ ◽  
SÁNDOR BARABÁS ◽  
LEVENTE CZEGLÉDI ◽  
ANDRÁS JÁVOR ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Parental Species ◽  
Molecular Genetic ◽  
Parallel Evolution ◽  
Carpathian Basin ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Aflp Data ◽  
F1 Hybrid

Although dysploidy and polyploidisation events are known to be important drivers in the evolutionary history of the genus Crocus, only a few examples of natural hybrid origins have so far been documented. Here, we describe the phylogenetic affinities of five taxa in the Crocus vernus species complex from the Carpathian Basin in Central Europe. Genetic variability was evaluated using chloroplast DNA sequences of the accD-psaI intergenic spacer and amplified fragment length polymorphism (AFLP) in combination with karyological observations. Genetic diversity and differentiation of the seven investigated Crocus species were also evaluated using AFLP data. We created a phylogenetic hypothesis using both sequences and AFLP fingerprinting data under maximum parsimony (MP). AFLPs were also analysed by means of multivariate statistics using principal coordinate (PCoA) analysis and Bayesian clustering (BC) to test for hybridity. Both the AFLP and plastid phylogenetic trees separated the taxa into two groups: (1) a ‘Balkan’ clade, and; (2) an ‘Adriatic’ clade. The Balkan clade contained Crocus heuffelianus samples and one Crocus vittatus from Croatia as well as Crocus tommasinianus samples from Hungary; the Adriatic clade included Crocus vittatus and Crocus vernus samples from Hungary and Croatia as well as Crocus neapolitanus from Italy. A hard incongruence was found in the placement of the Slovakian Crocus scepusiensis which clustered inside the Balkan clade on our plastid tree, while it fell in the Adriatic clade on the AFLP tree. The same populations occupied intermediate position on the PCoA plot. The BC analysis assigned all Crocus scepusiensis specimens as F1 hybrids, while Crocus vernus and Crocus heuffelianus were assigned as parental species. Together with our cytological investigation that determined a 2n=18 chromosome number of Crocus scepusiensis, we conclude an allopolyploid hybrid origin for this Northern Carpathian taxon as the result of a cross between members of the 2n=10 Balkan clade (e.g., Crocus heuffelianus from Transylvania) and the 2n=8 Adriatic clade (Crocus vernus). A similar origin is postulated for the North Balkan Crocus vittatus (2n=18), which was clustered as an F1 hybrid in the BC analysis; thus, parallel evolution may have taken place in the northern and southern part of the Carpathian Basin beginning from the same parental species but leading to different allopolyploid derivatives.

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