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

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.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weitao Chen ◽  
Ming Zou ◽  
Yuefei Li ◽  
Shuli Zhu ◽  
Xinhui Li ◽  
...  

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.


Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 99-105 ◽  
Author(s):  
J.J. Brown ◽  
D.G. Whittingham

Embryos of certain inbred mouse strains, and their F1 hybrids, are able to develop from the 1-cell to blastocyst stage in simple chemically defined media containing lactate (L), pyruvate (P) and glucose (G). The individual roles of these substrates in supporting complete preimplantation development in vitro was examined with 1-cell F2 embryos from B6CBF1 hybrid mice. Embryos collected between 26 and 27 h post hCG were cultured in medium containing L, P, LP or LPG. After 50 h in culture, the proportions developing to the morula stage were 1%, 83%, 94% and 100%, respectively. In combination, lactate and pyruvate appeared to act synergistically and both the rate and level of development to the morula stage were unaffected by the absence of glucose. After a further 46 h in culture, only the embryos grown in the presence of glucose developed into blastocysts. In LP medium, embryos arrested at the compacted morula stage late on day 3 of development. As culture continued in the absence of glucose, embryos decompacted (approximately 82 h post hCG) and subsequently degenerated. Exposure to medium containing glucose for the first, second or third 24 h period in culture was sufficient to support the morula-to-blastocyst transition. Glucose still supported this transition when embryos were transferred to LPG medium 3 h after the completion of compaction (76 h post hCG), but was ineffective 6 h later (82 h post hCG) once decompaction had commenced. We conclude that lactate and pyruvate together are able to support normal development of 1-cell F2 embryos to the morula stage in vitro, but that glucose is an essential component of the culture medium for development to the blastocyst stage.


Phytotaxa ◽  
2016 ◽  
Vol 258 (2) ◽  
pp. 121 ◽  
Author(s):  
ÁGNES MOSOLYGÓ-L ◽  
GÁBOR SRAMKÓ ◽  
SÁNDOR BARABÁS ◽  
LEVENTE CZEGLÉDI ◽  
ANDRÁS JÁVOR ◽  
...  

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.


2020 ◽  
Vol 48 (3) ◽  
pp. 1210-1220
Author(s):  
Tugce OZSAN ◽  
Ahmet N. ONUS

Globe artichoke [Cynara cardunculus var. scolymus (L.) Fiori] growing has gained commercial importance in recent years due to its consumption as food. It has also started to attract attention in pharmaceutics. Due to globe artichoke’s stated importance, growers need large amount of pathogen-free, healthy starting materials for production. Stated material will maximize the yield while minimizing the costs. Hybrid cultivars have uniform in height and maturity and could be harvested concurrently; on the other hand, an open-pollinated cultivar would have useful potential that could be smoothly produced locally at a lower cost. In vitro micropropagation enabling these goals as it serves large scale, fast, reliable and realistic alternative method to classic propagation via offshoots. The aim of the present study was to comparatively evaluate the micropropagation efficiency of two important local open-pollinated (OP) cultivars (‘Bayrampaşa’, ‘Sakız’) and five F1 hybrid cultivars (‘Olympus’, ‘Madrigal’, ‘Sambo’, ‘Green Globe’, ‘Imparator’), on the basis of total subcultures they were subjected to. Various plant growth regulators at various combinations were assessed for in vitro micropropagation and subsequent in vitro rooting. 3/4 basic MS medium supplemented with 0.05 mg  L-1 BA + 0.005 mg L-1 IBA was determined as the best media combination for in vitro micropropagation, while 10.0 mg L-1 IAA + 1.0 g L-1 activated charcoal adding to 1/2 basic MS medium had positive effects on in vitro rooting. According to results, the micropropagation efficiency varied based on cultivar differences and number of subcultures regardless of being OP or F1 hybrid. The present study demonstrated that in vitro propagation of globe artichoke could be a valuable process for assessing mass propagation regardless of using F1 or OP cultivars. Considering the OP cultivars are cheap in terms of price in a comparison to F1 hybrid cultivars, OP cultivars could be also recommended to be used for in vitro mass propagation. 


1975 ◽  
Vol 141 (3) ◽  
pp. 681-696 ◽  
Author(s):  
W L Ford ◽  
S J Simmonds ◽  
R C Atkins

A graft-vs.-host (GVH) reaction was initiated by the intravenous injection of parental strain (AO) lymphocytes into irradiated (AO times HO)F1 or (AO times DA)F1 hybrids. The proportion of donor T cells which had responded to the F1 hybrid antigens within 24 h was estimated by two methods. (a) Donor lymphocytes were labeled with [3H]uridine in vitro before injection. The proportion of labeled cells which had morphologically transformed in the recipient's spleen was 17-19%. In both series of experiments syngeneic transfers were performed in which case the proportion of transformed cells was 1-2.4%. A similar low proportion was found after parental to F1 transfer in a non-Ag-B strain combination. These figures were used to calculate the frequency of responding cells in the injected population given three additional pieces of information: (a) the extent of selection in the spleen which transformed the estimate to 4.5%-6.0% responders; (b) division of donor cells was shown to be negligible under the conditions of the experiment; and (c) the nonspecific recruitment of lymphocytes was shown to be negligible. A speculative model of antigen recognition by T cells which accounts for the high proportion of responders is outlined.


2018 ◽  
Vol 39 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Tijana Vučić ◽  
Tanja D. Vukov ◽  
Nataša Tomašević Kolarov ◽  
Milena Cvijanović ◽  
Ana Ivanović

In amphibians, morphological differentiation and disparity at the larval and post-metamorphic ontogenetic stages can diverge, owing to various contrasting environments and different selective pressures. In the monophyletic clade of nineTriturusnewt species, five different morphotypes can be recognized, but information on larval morphology is limited. Here we explore divergence of larval morphology inTriturus ivanbureschi,T. macedonicus, and their F1 hybrids. These two genetically and morphologically distinct crested newt species hybridize in nature and form a relatively wide hybrid zone in the central part of the Balkan Peninsula. Using a geometric morphometric approach and multivariate statistics, we evaluated differences of tail size and shape, colouration pattern, and the presence of a tail filament at the mid-larval stage in larvae reared under controlled laboratory conditions. We chose the tail as the main propulsive organ crucial for locomotion, feeding, and escaping predators. We found thatTriturus ivanbureschiandT. macedonicuslarvae differ in tail shape, but not in tail size. Two groups of F1 hybrid larvae (obtained from reciprocal crossing) were similar to each other, but differed from the parental species in size and shape of the tail, colouration pattern, and the presence of a tail filament. Our results indicate that, like adults, larvae diverge morphologically and hybrid larvae do not exhibit intermediate morphology of the parental species.


2019 ◽  
Author(s):  
Pragya Singh ◽  
Daniel Ballmer ◽  
Max Laubscher ◽  
Lukas Schärer

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.


2021 ◽  
Vol 2(26) ◽  
pp. 145-154
Author(s):  
S.B. Lepekhov ◽  

Creation of doubled haploid lines in wheat is a promising direction of research in Russia. However, the criteria for identifying good cross combinations, for which it is advisable to carry out androgenesis in vitro, have not been defined. One of these criteria could be the rate of heterosis in F1 or F2. The aim of this work was to establish the possibility of achieving the yield level of the F1 hybrid by the lines of later generations. The studies were carried out at the experimental fields of the FSBSI “Federal Altai Scientific Center for Agrobiotechnology” in 2017-2019. Varieties ‘Golubkovskaya’, ‘Omskaya 28’, ‘Saratovskaya 70’, F1 ‘Omskaya 28’ × ‘Saratovskaya 70’, F1 ‘Golubkovskaya’ × ‘Saratovskaya 70’, four breeding lines from cross ‘Golubkovskaya’ × ‘Saratovskaya 70’ and seven breeding lines from cross ‘Omskaya 28’ × ‘Saratovskaya 70’ were material for this research. Germination, survival rate, plant height, number of spikes per m2, plant biomass, number of spikelets per spike and grain per spike, 1000-seed weight, grain weight per spike and plant, harvest index, yield, duration of the “germination – ear formation” period, lodging resistance and leaf and stem rust resistance were examined. In three cases out of six, high-parent heterosis in the studied F1 hybrids was observed (yield increase – 3–19 %). Five cases of significant yield improvement in breeding lines compared to F1 hybrids were detected in 2017–2019 (additional yield 2–44 %). Lines exceeding hybrid F1 in the context of yield were taller (+5–30 cm), with more extended period “germination – ear formation” (+7–8 days), higher plant biomass (+1.24–5.16 g), a larger number of spikelets per spike (0.5–2.8 units) and larger number of kernels (+3.5–8.0 units). Pure lines of soft spring wheat can be compared in yield to F1 hybrid, from which they were obtained. This fact was possible due to the selection of lines for desired traits determined by recessive genes.


2020 ◽  
Author(s):  
Rongli Liao ◽  
Weibang Sun ◽  
Yongpeng Ma

Abstract Background: F1 hybrids acting as a bridgehead for producing later generation hybrids can have evolutionary significance through strengthening reproductive isolation or facilitating gene flow between parental species, depending on whether backcrossing can occur. It had been suggested that the Tibetan plant Buddleja wardii was a hybrid species between B. alternifolia and B. crispa based on their sympatric distributions and the morphological characters in last century. Till now however, we still have limited evidence to prove key issues to B. wardii, like if it is of hybrid origin indeed and whether it is currently a true hybrid species already.Results: In the present study, two sympatric populations of these three taxa were examined and compared using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii was likely to be a hybrids between B. alternifolia and B. crispa, and moreover, most of the hybrids present were confirmed to be F1s. This was further supported by morphology as no transgressive characters were detected. B. crispa was found to be the maternal parent in one population (BH), while in the second population (TJ), it was difficult to distinguish the hybridization direction due to shared haplotypes of cpDNA between B. alternifolia and B. crispa. Conclusions: These results provide evidence that the natural hybrids between B. alternifolia and B. crispa mainly comprise F1 hybrids, which have subsequently been given the name B. wardii. The F1 hybrids have also contributed to strong reproductive isolation between parental species.


1967 ◽  
Vol 29 (1-4) ◽  
pp. 139-214 ◽  
Author(s):  
William Franklin Childers

Red-ear sunfish, Lepomis microlophus (Gunther); bluegill, L. macrochiris Rafinesque; green sunfish, L. cyanellus Rafinesque; and warmouth, Chaenobryttus gulosus (Cuvier) are present in a number of east-central Illinois lakes and ponds and are known to hybridize occasionally. During 1957 through 1964, the spawning seasons of these species were observed to extend from mid-May to August or September. Red-ear sunfish, bluegills, and green sunfish usually nested in colonies, and mixed colonies containing two and, less frequently, all three of these species were not uncommon. Warmouths tended to be more solitary in their nest site selections. Gametes stripped from the four species were paired in 16 different combinations to produce zygotes representing 12 kinds of F1 hybrids and the four parental species.  warmouth male x bluegill female and warmouth male X red-ear female crosses were 100 percent lethal, and the warmouth male x green sunfish female cross was partially lethal.  Based on the percentages of zygotes that hatched and developed into normal-appearing fry, the viability of each of the remaining nine kinds of hybrids was not significantly different from that of its maternal parent.


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