Trends in evolution of the Rhodniini tribe (Hemiptera, Triatominae): experimental crosses between Psammolestes tertius Lent & Jurberg, 1965 and P. coreodes Bergroth, 1911 and analysis of the reproductive isolating mechanisms

Abstract Background The tribe Rhodniini is a monophyletic group composed of 24 species grouped into two genera: Rhodnius and Psammolestes. The genus Psammolestes includes only three species, namely P. coreodes, P. tertius and P. arthuri. Natural hybridization events have been reported for the Rhodniini tribe (for genus Rhodnius specifically). Information obtained from hybridization studies can improve our understanding of the taxonomy and systematics of species. Here we report the results from experimental crosses performed between P. tertius and P. coreodes and from subsequent analyses of the reproductive and morphological aspects of the hybrids. Methods Crossing experiments were conducted between P. tertius and P. coreodes to evaluate the pre- and post-zygotic barriers between species of the Rhodniini tribe. We also performed cytogenetic analyses of the F1 hybrids, with a focus on the degree of pairing between the homeologous chromosomes, and morphology studies of the male gonads to evaluate the presence of gonadal dysgenesis. Lastly, we analyzed the segregation of phenotypic characteristics. Results Interspecific experimental crosses demonstrated intrageneric genomic compatibility since hybrids were produced in both directions. However, these hybrids showed a high mortality rate, suggesting a post-zygotic barrier resulting in hybrid unviability. The F1 hybrids that reached adulthood presented the dominant phenotypic segregation pattern for P. tertius in both directions. These insects were then intercrossed; the hybrids were used in the cross between P. tertius ♀ × P. coreodes ♂ died before oviposition, and the F1 hybrids of P. coreodes ♀ x P. tertius ♂ oviposited and their F2 hybrids hatched (however, all specimens died after hatching, still in first-generation nymph stage, pointing to a hybrid collapse event). Morphological analyses of male gonads from F1 hybrids showed that they did not have gonadal dysgenesis. Cytogenetic analyses of these triatomines showed that there were metaphases with 100% pairing between homeologous chromosomes and metaphases with pairing errors. Conclusion The results of this study demonstrate that Psammolestes spp. have intrageneric genomic compatibility and that post-zygotic barriers, namely unviability of hybrid and hybrid collapse, resulted in the breakdown of the hybrids of P. tertius and P. coreodes, confirming the specific status of species based on the biological concept of species. Graphical abstract

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Recent Records of Hybridization Between Barred Owls (Strix Varia) and Northern Spotted Owls (S. Occidentalis Caurina)

The Auk ◽

10.1093/auk/121.3.806 ◽

2004 ◽

Vol 121 (3) ◽

pp. 806-810

Author(s):

Elizabeth G. Kelly ◽

Eric D. Forsman

Keyword(s):

First Generation ◽

F1 Hybrids ◽

Tissue Samples ◽

Spotted Owl ◽

Strix Varia ◽

Isolating Mechanisms ◽

Spotted Owls ◽

Direct Competition ◽

Northern Spotted Owls ◽

Barred Owls

Abstract We summarized records of hybridization between Barred Owls (Strix varia) and Northern Spotted Owls (S. occidentalis caurina) in Washington and Oregon through 1999. A total of 47 hybrids were observed, including 17 F1s that were first detected as adults, 4 F1s that were banded as juveniles and subsequently recaptured as adults, 10 F1 juveniles, and 16 F2 juveniles. All confirmed cases of hybridization between Barred and Spotted owls involved male Spotted Owls paired with female Barred Owls. Ten F1 hybrids that backcrossed with Barred Owls produced a total of 15 young; 6 F1 hybrids that backcrossed with Spotted Owls produced only 1 young. Those differences may indicate that some combinations of sex and species are more compatible or more fertile than others, but more documentation is needed. Because F2 hybrids and subsequent generations are difficult to distinguish in the field from Barred or Spotted owls, genetic comparisons of blood or tissue samples may be needed to identify hybrids beyond the first generation. The small number of F1 hybrids detected during many years of extensive banding studies of Spotted Owls suggests that the isolating mechanisms that separate Barred and Spotted owls are normally sufficient to avoid hybridization between them. Direct competition between the two species for food and space is probably a much more serious threat to the Spotted Owl than hybridization.

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Natural hybridization between an outcrossing and a selfingPhlox (Polemoniaceae): The maternal species of F1 hybrids

Plant Systematics and Evolution ◽

10.1007/bf01087043 ◽

1999 ◽

Vol 218 (1-2) ◽

pp. 153-158 ◽

Cited By ~ 21

Author(s):

Carolyn J. Ferguson ◽

Donald A. Levin ◽

Robert K. Jansen

Keyword(s):

Natural Hybridization ◽

F1 Hybrids

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Unidirectional Natural Hybridization between Brown Trout (Salmo trutta) and Atlantic Salmon (S. salar) in Newfoundland

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f92-216 ◽

1992 ◽

Vol 49 (9) ◽

pp. 1953-1958 ◽

Cited By ~ 51

Author(s):

Colin McGowan ◽

William S. Davidson

Keyword(s):

Atlantic Salmon ◽

Brown Trout ◽

Salmo Trutta ◽

Dna Analysis ◽

Juvenile Fish ◽

Natural Hybridization ◽

Major Influence ◽

Isolating Mechanisms ◽

Brown Trout Salmo Trutta ◽

Sexually Mature

Protein electrophoresis and mitochondrial DNA analysis were used to detect the frequency and direction of natural hybridization between brown trout (Salmo trutta) and Atlantic salmon (S. salar) in nine Newfoundland rivers. In total, 37 hybrids were discovered in a sample of 792 juvenile fish for a regional frequency of 4.67%. Local frequencies ranged from 0.00 to 18.75% and were significantly heterogeneous. All of the hybrids sampled were produced from matings between female brown trout and male Atlantic salmon. Possible reasons for the breakdown of prereproductive isolating mechanisms between these species are considered. Reproductive characteristics of the populations involved appear to have a major influence on the dynamics of hybridization between these species in Newfoundland. It is proposed that an abundance of sexually mature Atlantic salmon parr in Newfoundland streams is responsible for both the frequency and direction of hybridization observed in this study.

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Detection and Effects of a Homeologous Reciprocal Transposition in Brassica napus

Genetics ◽

10.1093/genetics/165.3.1569 ◽

2003 ◽

Vol 165 (3) ◽

pp. 1569-1577

Author(s):

Thomas C Osborn ◽

David V Butrulle ◽

Andrew G Sharpe ◽

Kathryn J Pickering ◽

Isobel A P Parkin ◽

...

Keyword(s):

Brassica Napus ◽

Genetic Mapping ◽

Doubled Haploid ◽

Selective Advantage ◽

F1 Hybrids ◽

Rflp Markers ◽

Cytological Analysis ◽

Linkage Groups ◽

Homeologous Chromosomes ◽

Seed Yields

Abstract A reciprocal chromosomal transposition was identified in several annual oilseed Brassica napus genotypes used as parents in crosses to biennial genotypes for genetic mapping studies. The transposition involved an exchange of interstitial homeologous regions on linkage groups N7 and N16, and its detection was made possible by the use of segregating populations of doubled haploid lines and codominant RFLP markers. RFLP probes detected pairs of homeologous loci on N7 and N16 for which the annual and biennial parents had identical alleles in regions expected to be homeologous. The existence of an interstitial reciprocal transposition was confirmed by cytological analysis of synaptonemal complexes of annual × biennial F1 hybrids. Although it included approximately one-third of the physical length of the N7 and N16 chromosomes, few recombination events within the region were recovered in the progenies of the hybrids. Significantly higher seed yields were associated with the parental configurations of the rearrangement in segregating progenies. These progenies contained complete complements of homeologous chromosomes from the diploid progenitors of B. napus, and thus their higher seed yields provide evidence for the selective advantage of allopolyploidy through the fixation of intergenomic heterozygosity.

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Unravelling the hybrid vigor in domestic equids: the effect of hybridization on bone shape variation and covariation

BMC Evolutionary Biology ◽

10.1186/s12862-019-1520-2 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 4

Author(s):

Pauline Hanot ◽

Anthony Herrel ◽

Claude Guintard ◽

Raphaël Cornette

Keyword(s):

First Generation ◽

Shape Change ◽

Morphological Integration ◽

Hybrid Vigor ◽

F1 Hybrids ◽

Shape Variation ◽

Locomotor System ◽

Domestic Horses ◽

Functional Mechanisms ◽

Underlying Processes

Abstract Background Hybridization has been widely practiced in plant and animal breeding as a means to enhance the quality and fitness of the organisms. In domestic equids, this hybrid vigor takes the form of improved physical and physiological characteristics, notably for strength or endurance. Because the offspring of horse and donkey is generally sterile, this widely recognized vigor is expressed in the first generation (F1). However, in the absence of recombination between the two parental genomes, F1 hybrids can be expected to be phenotypically intermediate between their parents which could potentially restrict the possibilities of an increase in overall fitness. In this study, we examine the morphology of the main limb bones of domestic horses, donkeys and their hybrids to investigate the phenotypic impact of hybridization on the locomotor system. We explore bone shape variation and covariation to gain insights into the morphological and functional expressions of the hybrid vigor commonly described in domestic equids. Results Our data reveal the occurrence of transgressive effects on several bones in the F1 generation. The patterns of morphological integration further demonstrate that the developmental processes producing covariation are not disrupted by hybridization, contrary to functional ones. Conclusions These results suggest that an increase in overall fitness could be related to more flexibility in shape change in hybrids, except for the main forelimb long bones of which the morphology is strongly driven by muscle interactions. More broadly, this study illustrates the interest of investigating not only bone shape variation but also underlying processes, in order to contribute to better understanding how developmental and functional mechanisms are affected by hybridization.

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Успадкування господарсько цінних ознак у гібридів F1 квасолі звичайної в умовах Лівобережної частини Лісостепу України

Вісник Полтавської державної аграрної академії ◽

10.31210/visnyk2013.01.07 ◽

2013 ◽

pp. 33-36

Author(s):

С. І. Силенко ◽

О. С. Силенко

Keyword(s):

Seed Yield ◽

First Generation ◽

Seed Mass ◽

Growing Season ◽

F1 Hybrids ◽

Lower Tier ◽

Number Of Seeds

Доведено, що ступінь фенотипового домінування у гібридів F1 може варіювати від hp > +1 до hp < -1 залежно від компонентів схрещування. Встановлено, що переважна більшість гібридів F1 тривалість веґетаційного періоду та його міжфазних періодів успадковують за типами позитивного наддомінування та позитивним домінуванням. Успадкування висоти рослин відбувається за типами позитивного домінування, проміжного успадкування та за типом негативного домінування. Характер успадкування висоти прикріплення нижнього ярусу бобів у значній мірі визначається поєднанням батьківських компонентів. Так, у першому поколінні у гібридних комбінаціях спостерігається явище наддомінування. За ознаками урожайності та її елементів (урожайність насіння, маса насіння з рослини, маса 1000 насінин, кількість бобів на рослині, кількість насінин із рослини, кількість насінин у бобі) у всіх без виключення гібридів першого покоління спостерігався гетерозис. It was demonstrated that the degree of phenotypic predominance in F1 hybrids can vary from hp to hp < +1 > -1 depending on mating components. The vast majority of the F1 hybrids inherit the length of the growing season and its interphase by type of over& positive dominance. F1 hybrids inherit the height of plants by types of positive dominance, intermediate inheritance and negative domination. The height of the attachment of the lower tier of the beans is largely determined by a combination of parent components. Thus, in the first generation in hybrid combinations there is the phenomenon of over dominance. Due to the yield and its components (seed yield, seed mass per plant, 1000 seeds, number of beans per plant, number of seeds per plant, number of seeds per seedpod) in all first generation hybrids heterosis is observed.

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Ongoing production of low-fitness hybrids limits range overlap between divergent cryptic species

10.1101/2021.02.09.430089 ◽

2021 ◽

Author(s):

Else K. Mikkelsen ◽

Darren Irwin

Keyword(s):

First Generation ◽

Sex Chromosome ◽

Genomic Variation ◽

F1 Hybrids ◽

The Pacific ◽

Species Pairs ◽

Genetic Clusters ◽

Range Overlap ◽

Female Specific

AbstractContact zones between recently-diverged taxa provide opportunities to examine the causes of reproductive isolation and to examine the processes that determine whether two species can coexist over a broad region. The Pacific Wren (Troglodytes pacificus) and the Winter Wren (Troglodytes hiemalis) are two morphologically similar songbird species that started diverging about 4 million years ago, older than most sister species pairs. The ranges of these species come into narrow contact in western Canada, where the two species remain distinct in sympatry. To assess evidence for differentiation, hybridization, and introgression in this system, we examined variation in over 250,000 single nucleotide polymorphism markers distributed across the genomes of the two species. The two species formed highly divergent genetic clusters, consistent with long-term differentiation. In a set of 75 individuals from allopatry and sympatry, two first-generation hybrids (i.e., F1’s) were detected, indicating only moderate levels of assortative mating between these taxa. We found no recent backcrosses or F2’s or other evidence of recent breeding success of F1 hybrids, indicating very low or zero fitness of F1 hybrids. Examination of genomic variation shows evidence for only a single backcrossing event in the distant past. The sizeable rate of hybridization combined with very low fitness of F1 hybrids is expected to result in a population sink in the contact zone, largely explaining the narrow overlap of the two species. If such dynamics are common in nature, they could explain the narrow range overlap often observed between pairs of closely related species. Additionally, we present evidence for a rare duplication of a large chromosomal segment from an autosome to the W chromosome, the female-specific sex chromosome in birds.

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The study of the nature of the inheritance of quantitative traits in F1 hybrids of winter soft wheat

BIO Web of Conferences ◽

10.1051/bioconf/20201700084 ◽

2020 ◽

Vol 17 ◽

pp. 00084

Author(s):

Olga Antoshina ◽

Julia Odnodushnova ◽

Gennadiy Fadkin ◽

Irina Kondakova ◽

Olga Fedosova

Keyword(s):

Quantitative Traits ◽

First Generation ◽

Grain Weight ◽

Soft Wheat ◽

F1 Hybrids ◽

Complex Nature ◽

Intraspecific Hybridization ◽

Quantitative Characteristics ◽

Economically Valuable Traits ◽

Ear Number

In the conditions of the south of the Nonchernozem Zone, intraspecific hybridization of winter soft wheat was carried out. When selecting parental forms used in crossing, special attention was paid to such economically valuable traits as productive tilling capacity, the number of grains and the mass of grain per spike. The true (Htru) and hypothetical heterosis (Hhyp) on the basis of “plant height”, “length of the lower internode”, “length of the upper internode”, “general tilling capacity”, “productive tilling capacity”, “spike length”, “number of spikelets”, “number of grains” and “grain weight per spike” were determined. It was established that the inheritance of quantitative traits in hybrids of the first generation was distinguished by the complex nature of distribution by types. Studies have made possible to identify 5 hybrid combinations F1, in which the effect of heterosis manifests itself simultaneously on five quantitative characteristics (ear length, number of spikelets per ear, number of grains per ear, grain weight per ear, mass grain from a plant).

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Morphology and fitness components of wild × crop F1 hybrids of Sorghum bicolor (L.) in Ethiopia: implications for survival and introgression of crop genes in the wild pool

Plant Genetic Resources ◽

10.1017/s1479262113000129 ◽

2013 ◽

Vol 11 (3) ◽

pp. 196-205 ◽

Cited By ~ 6

Author(s):

Asfaw Adugna ◽

Endashaw Bekele

Keyword(s):

Risk Assessment ◽

Natural Hybridization ◽

Relative Fitness ◽

F1 Hybrids ◽

Transgenic Crop ◽

Fitness Components ◽

Crop Species ◽

In The Wild ◽

Sorghum Bicolor L ◽

Made In

Natural hybridization between wild/weedy and crop species often results in rare hybrids, which can be more weedy and difficult to control. Moreover, the advent of transgenic crop plants raises questions of biosafety risk assessment on the consequences of rare hybrids with possible fitness enhancing genes on the environment. This study aimed at measuring the fitness components of wild–crop sorghum hybrids for various juvenile survival and adult morphological and fertility characters as part of the risk assessment of transgenic sorghum in Africa where the crop was believed to have first domesticated and serves as the major staple. Out of a pool of hybrids made in 2010 from 23 wild sorghum accessions and two released cultivated sorghum varieties using hand emasculation techniques, seven were selected for the field study of their fitness components in 2011. The study confirmed that crop–wild hybrids of sorghum are fertile. Two approaches were followed (relative fitness and mid-parent heterosis) which showed that most of the hybrids were as fit as their wild parents, and in some cases they showed mid-parent heterosis for the measured traits. The results of this study highlighted a potential risk that hybrids carrying crop genes (including herbicide resistance transgenes) could pose because they could be more weedy than their wild/weedy parents if transgenic sorghum is deployed in regions where the wild and cultivated sorghum populations coexist, such as in Ethiopia and in other parts of Africa.

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Contrasting Success of Natural Hybridization in Two Eucalyptus Species Pairs

Australian Journal of Botany ◽

10.1071/bt9800167 ◽

1980 ◽

Vol 28 (2) ◽

pp. 167 ◽

Cited By ~ 4

Author(s):

DW Drake

Keyword(s):

Principal Component ◽

Flowering Phenology ◽

Natural Hybridization ◽

F1 Hybrids ◽

Hybrid Population ◽

Eucalyptus Species ◽

Major Barrier ◽

Species Pairs ◽

Plant Hybridization ◽

Hybrid Number

A morphological study with univariate and principal component analyses of mature tree and open-pollinated seedling populations shows that natural hybridization is occurring between Eucalyptus melanophloia and E. crebra, and E. populnea and E. crebra (subgenus Symphyomyrtus, section Adnataria). The level of successful hybridization in these two systems, where fundamental genetic (reproductive) and ecological (habitat and spatial) barriers are absent, is examined. Within the ecotone, hybrids between E. melanophloia and E. crebra are about one-fifth as frequent as those between E. populnea and E. crebra. Analyses of the phenotype/genotype compositions of the hybrid populations, the patterns of segregation, and outcrossing frequencies between the species pairs indicate the level of development of the hybrid populations. All E. melanophloia × E. crebra hybrids appear to be F1 hybrids. In contrast, the E.populnea x E. crebra hybrid population attains a much higher level of development in terms of both hybrid number and genotypic complexity. Flowering phenology is a major barrier to E. melanophloia × E. crebra hybrid formation compared with the other hybrids, although it is considered an incomplete barrier and alone may not explain the diversity of hybrid success which occurs.A theory of plant hybridization which incorporates the concept of hybridization success is presented and discussed in relation to the two hybridizing systems, as a basis for further investigating the mechanisms involved.

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