Morphology Of Genitalia Research Articles

Coevolution of male and female reproductive structures in Drosophila

The morphology of male genitalia whilst stable within species, exhibits huge interspecific variation. This variation is likely to be as a result of sexual selection due to the direct involvement of these reproductive structures in mating and sperm transfer. In contrast, internal soft tissue components of the genitalia are generally poorly investigated as they are not directly involved in physical and mechanical adequacy during sperm transfer. However, these soft tissue structures may also drive differential male-female interactions, particularly in internally fertilising organisms where females have the ability to store sperm and bias male reproductive success. In this paper we use the drosophila model to investigate the role of male and female reproductive elements in sexual selection. Our meta-analysis supplemented with additional new data clearly shows that within species, sperm length versus testis length, and sperm length versus seminal receptacle length, are highly correlated. Thus, independent of the phylogenetic relationship among species, gamete evolution is likely to result in sexual selection interactions that drive the evolution of internal reproductive components in both sexes. Our results and discussion of the literature highlight the importance of considering internal soft structures that may influence fertilisation, when investigating selective forces acting on the evolution of reproductive traits.

Postcopulatory sexual selection: Darwin's omission and its consequences.

In one of his few major oversights, Darwin failed to appreciate that male-male competition and sexual selection can continue even after copulation has begun. The postcopulatory equivalents of both direct male-male battles (sperm competition) and female choice (cryptic female choice) occur within the female's body. Recognition of this hidden, but intense, sexual competition provides new insights into a variety of fields. These include the hyperdiverse and paradoxically elaborate morphology of both sperm and male genitalia, the equally puzzling and elaborate morphology of nongenitalic male structures that are specialized to grasp and stimulate females, powerful manipulative effects of substances in male semen on female reproductive physiology, paradoxical male courtship behavior that occurs after copulation has already begun, variability in parental investments, and the puzzlingly complex and diverse interactions between sperm and female products that surround animal eggs and between male gametophytes and female tissues in flowering plants. Many bizarre traits are involved, including male genitalia that are designed to explode or fall apart during copulation leaving behind parts within the female, male genitalia that "sing" during copulation, potent seminal products that invade the female's body cavity and her nervous system to influence her behavior, and a virtual Kama Sutra of courtship behavior performed after rather than before genital coupling, including male-female dialogues during copulation.

Discovery of a second species of Aesalini from continental China, with description of the new species and its third instar larva (Coleoptera: Scarabaeoidea: Lucanidae)

Aesalus zhejiangensis Huang & Bi, sp. nov. is described from Mt. Fengyangshan, southern Zhejiang, China. It is the second species of the lucanid genus Aesalus Fabricius known from continental China. This new species is similar to the Indo-Chinese species Aesalus satoi, but can be distinguished by the longer canthus, male with shorter non-sclerotized distal portion of penis (medial lobe of parameres), and female genitalia with longer styli. A checklist of Aesalini and a key to the Old World species are given. Female genitalia and larval morphology are described in detail for the new species and discussed for the higher classification of Aesalini. The current state of Aesalini systematics and phylogeny is discussed.

The functional morphology of the male genitalia in the Gelichiid-moth genera Holcophora Stgr., Ananarsia Ams., and Nothris Hbn. (Lepidoptera, Gelechiidae: Gelechiini, Dichomeridini)

The functional morphology of the male genitalia of Holcophora statices Stgr., Nothris verbascella (Den. et Schiff.) and Ananarsia lineatella (Zell.) is described. The genus Holcophora Hbn. is placed into the tribe Gelechiini based on the peculiarities of the skeleton-muscular apparatus of the male genitalia. Ananarsia Ams. is treated as a separate genus owing to a complex of differences from the genus Anarsia Zell. in skeleton-muscular apparatus of the male genitalia. The relationships between Nothris Hbn. and the tribe Chelariini is confirmed by characters of the functional morphology of the male genitalia.

A survey of the genus Geometra Linnaeus (Lepidoptera, Geometridae, Geometrinae)

The type genus of the family Geometridae, Geometra Linnaeus, is reviewed. In addition to the 16 species known worldwide, two new species are described: Geometra neovalida sp. nov. from China, and Geometra burmensis sp. nov. from Burma (Myanmar). All the known species are redescribed. Genitalia of all species are described and illustrated, most for the first time. Generic characters based on all species are summarized. The monophyly of the genus and its relationship with allied genera are reviewed and discussed in detail. Most species fall into two species groups, named the papilionaria and smaragdus groups, on the basis of the morphology of the male genitalia. Biological information is provided where available. Illustrations of moths and genitalia are presented.

Natural selection and genital variation: a role for the environment, parasites and sperm ageing?

Male genitalia are more variable between species (and populations) than other organs, and are more morphologically complex in polygamous compared to monogamous species. Therefore, sexual selection has been put forward as the major explanation of genital variation and complexity, in particular cryptic female choice for male copulatory courtship. As cryptic female choice is based on differences between males it is somewhat paradoxical that there is such low within-species variation in male genitalia that they are a prime morphological identification character for animal species. Processes other than sexual selection may also lead to genitalia variation but they have recently become neglected. Here I focus on pleiotropy and natural selection and provide examples how they link genitalia morphology with genital environments. Pleiotropy appears to be important because most studies that specifically tested for pleiotropic effects on genital morphology found them. Natural selection likely favours certain genital morphology over others in various environments, as well as by reducing re-infection with sexually transmitted diseases or reducing the likelihood of fertilisation with aged sperm. Both pleiotropy and natural selection differ locally and between species so may contribute to local variation in genitalia and sometimes variation between monogamous and polygamous species. Furthermore, the multitude of genital environments will lead to a multitude of genital functions via natural selection and pleiotropy, and may also contribute to explaining the complexity of genitalia.

Morfologia comparada da genitália masculina de Galerucini (Coleoptera, Chrysomelidae, Galerucinae)

The morphology of the genitalia, especially of the male, has been used to elucidate taxonomical and evolutive questions in chrysomelids, particularly Galerucini. In this contribution, we selected genera representing the Nearctic and Neotropical subtribes of Galerucini. We provide comparative descriptions and illustrations of male genitalia of six species: Coelomera lanio (Dalman, 1823) and Dircema nigripenne (Fabricius, 1792) (Subtribe Galerucina); Exora encaustica (Germar, 1824) and Uaupesia amazona (Weise, 1921) (Subtribe Metacyclina); Paranapiacaba teinturieri (Allard, 1894) and Isotes eruptiva (Bechyne, 1955) (Subtribe Luperina). The spiculum gastrale is present in the studied species of Metacyclina and Luperina. In the median lobe, basal spurs directed ventrad do not occur only in P. teinturieri and I. eruptiva; these species present a hood-like process protecting the basal orifice. The subbasal fenestra is observed in C. lanio and U. amazona; the flagellum, an internal sac sclerite, occurs only in U. amazona. The morphology of Galerucini male genitalia is still poorly known and further studies including other genera are needed.

Обзор видов рода Pediasia Hübner, [1825] (Lepidoptera: Pyraloidea, Crambidae) фауны Дальнего Востока России

An annotated list of far eastern Pediasia is given, including detailed data on their morphology, ecology and distribution. The keys for species identification basing on external morphology and morphology of both males and females genitalia are proposed. Pediasia luteella ([Denis & Schiffermüller], 1775) and Pediasia radicivitta (Filipjev, 1927) are reported from the Russian Far East for the first time.

Morphological and mitochondrial DNA analyses indicate the presence of a hybrid zone between two species of leaf beetle (Coleoptera; Chrysomelidae) in Southern Spain

The present study reports a case where the survey of morphological and mitochondrial DNA variation among populations of a species complex of leaf beetle, the Gonioctena variabilis complex, has lead to the identification of a hybrid zone between two species of the complex in Southern Spain. The complex is divided into four species distributed around the western Mediterranean region. The four species, G. variabilis, Gonioctena aegrota, Gonioctena gobanzi, and Gonioctena pseudogobanzi, are traditionally determined by differences in the morphology of the male genitalia (aedeagus). To gain insight into the history of the speciation process within this species complex, we sampled populations in Portugal, Spain, Southern France, and Northern Italy. We sequenced a portion of the mitochondrial control region of each individual collected. A haplotype network of these sequences was found to comprise four distinct groups of sequence types, separated by a relatively large number of mutations. Moreover, in most of the samples for which morphological and molecular variation is available, there is a one-to-one correspondence between haplotype group, defined by mitochondrial sequence variation, and morphological groups defined on the basis of the aedeagus, showing evidence of four historically independent evolutionary units. This supports the use of the aedeagus morphology as a taxonomically informative trait in this species complex and a recent taxonomic revision upgrading four formerly subspecies, corresponding to the evolutionary units identified in the present study, to species status. However, some of the individuals from our samples in Southern Spain, morphologically identified as G. aegrota, were found to possess mitochondrial sequences typical of G. pseudogobanzi. The opposite case was also found. This suggests the presence of a zone of contact and hybridization between G. aegrota and G. pseudogobanzi. The location of this hybrid zone appears to be unusual. We identify historical scenarios that may explain our observations. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 105–114.

Rhopalopyx cigigas sp. n. from central Italy (Hemiptera, Auchenorrhyncha, Cicadellidae)

Rhopalopyx cigigas, a new species from Central Italy, is described. Its fundamental features lie in the size and in the morphology of the male genitalia (in particular of the aedeagus, anal tube and process of the pygofer lobes). R. cigigas lives on several mountains of Central Italy. Adults were collected in August from 1800 to 2200 m, on grasses.

New Ladybirds from Southern Africa (Coleoptera, Coccinellidae)

Two new coccinellid species from Southern Africa are described, Hyperaspis kochi sp. n. (type locality: South Africa: Northern Province: Lekgalameetse Nature Reserve) and Scotoscymnus punctatissimus sp. n. (type locality: South Africa: KwaZulu-Natal: Sodwana Bay National Park), and compared with the closely related species. A key to the South African Hyperaspis species is provided. Mainly body outlines and the morphology of genitalia are used as distinctive characters.

Identificación molecular de especies crípticas de trichogramma westwood (hymenoptera: trichogrammatidae) de importancia agrícola en México

La identificación de las avispas parasitoides del género Trichogramma es difícil debido a su tamaño pequeño y a la plasticidad de sus características morfológicas. La morfología de genitalias y antenas de los machos es de utilidad para determinar las especies, sin embargo esto representa un problema en particular cuando las especies se reproducen por partenogénesis. El objetivo del presente trabajo fue identificar a nivel molecular especies crípticas de Trichogramma de importancia agrícola en México. Se identificó a las especies crípticas T. pretiosum, T. fuentesi y T. exiguum, así como a las no crípticas T. atopovirilia y T. pintoi. Se construyó una clave dicotómica de identificación, basada en el tamaño del espaciador transcrito interno 2 (ITS2) del DNA ribosomal amplificado por PCR, y el polimorfismo en la longitud de los fragmentos de restricción entre las especies. Las regiones ITS2 fueron secuenciadas y comparadas con secuencias de GenBank, se calcularon los porcentajes de similitud y divergencia entre las especies. Esta herramienta molecular puede resolver la identificación de especies crípticas presentes en México.

A new concept of the generic composition of the geometrid moth tribe Ennomini (Lepidoptera, Geometridae) based on functional morphology of the male genitalia

Two unique apomorphies in the skeleto-muscular apparatus of the male genitalia in a series of genera of the subfamily Ennominae have been discovered: (1) a more or less broad membranous area on the ventral side of the vinculum, partly or completely dividing this sclerite along the sagittal plane, and (2) the paired muscle m 3 attached distally to the medial invagination of the basal portion of the juxta. Such a structure provides resilient flexion of the ventral portion of the vinculum in the sagittal plane as the valvae are abducted by contraction of muscle m 3. Based on these apomorphies and taking into account the general morphological pattern in the Ennominae, a new generic composition of the tribe Ennomini including 148 valid genera is proposed. A new diagnosis for Ennomini as a monophyletic group is given, with the following synonymy of the family group names established: Ennomini sensu novo = Urapteridae, syn. n.; = Odopteridi; = Emplocidae, syn. n.; = Oxydiidae, syn. n.; = Pantheridae, syn. n.; = Nephodiinae, syn. n.; = Leuculinae, syn. n.; = Cingiliini, syn. n. The musculature of the male genitalia in Ennomos infidelis and Ourapteryx koreana is described for the first time and that of Tristrophis veneris is revised. The American origin of the tribe Ennomini is hypothesized. The mainly Palaearctic tribe Prosopolophini is regarded as a probable sister group of Ennomini sensu novo.

The evolution of male genitalia: functional integration of genital sclerites in the dung beetle Onthophagus taurus

It is now widely recognized that sexual selection has been important in the rapid and divergent evolution of male genital morphology. However, distinguishing among putative mechanisms of sexual selection acting on male genital morphology represents a considerable challenge. Although there is growing evidence that variation in the size and/or shape of male genital structures can determine a male’s success in gaining fertilizations, our knowledge of the functional morphology of male genitalia remains limited. Here we examine the functional morphology of genital sclerites that are known to influence paternity in the dung beetle Onthophagus taurus. We show that three of the sclerites form a functionally integrated unit that generates the tubular-shaped spermatophore and delivers its opening to the female’s spermathecal duct. A fourth sclerite acts as a holdfast device during copulation. Our observations shed light on the mechanism by which these sclerites influence a male’s paternity, and their patterns of phenotypic and genetic (co)variation. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 257–266. ADDITIONAL KEYWORDS: cryptic female choice – male genital morphology – paternity – sexual selection – sperm competition.

Molecular Characterization of 6 Unrelated Italian Patients With 5α‐Reductase Type 2 Deficiency

Steroid 5alpha-reductase (5alphaR) deficiency (OMIM number #264600) is a rare 46,XY disorder of sex differentiation caused by mutations in the 5alphaR type 2 gene (SRD5A2) resulting in dihydrotestosterone deficiency during fetal development. We report on the analysis of the SRD5A2 gene in 6 unrelated 46,XY Italian patients with external genitalia morphology ranging from predominantly female to nearly completely male. Three subjects were seen and assessed at birth, 1 patient was referred to us before puberty, and 2 at postpubertal age. Six different causative mutations (5 missense and 1 nonsense) and a rare polymorphism were identified. Four patients presented homozygous single-base substitutions. These SRD5A2 mutations were located in exon 2 (variant Cys133Gly), exon 4 (Gly196Ser and Ala207Asp) and exon 5 (Tyr235Phe). A fifth subject was a compound heterozygote who carried a nonsense mutation in exon 1 (Trp53X) and a second SRD5A2 alteration in exon 5 (Tyr235Phe). The final patient presented a mutation in only 1 allele (Gly34Trp) together with the Ala49Thr variant. The molecular characterization of these patients made it possible to identify novel mutations and to confirm, before gender assignment or any surgical approach, the suspected 5alphaR deficiency in 2 newborns, 1 of whom had inconclusive hormonal data. 5alphaR deficiency in subjects without parental consanguinity and the presence of compound heterozygotic patients suggest that SRD5A2 mutations carrier frequency may be higher than previously thought.

Phylogeny of the Limnophilinae (Limoniidae) and early evolution of the Tipulomorpha (Diptera)

Tipulomorpha (crane flies) comprise one of the largest subgroups of Diptera, but its phylogeny at different levels has been poorly explored. This study presents the most comprehensive cladistic analysis of the group ever made, with emphasis on the genera and subgenera of the subfamily Limnophilinae (Limoniidae), assumed to include some of the earliest lineages of Tipulomorpha sensu stricto and therefore important for the understanding of the early patterns in the evolution of the crane flies. Eighty-eight characters of the male imago were scored for 104 exemplar species. The most parsimonious trees were searched using implied weighting, in the framework of a sensitivity analysis with different values of k (2 to 6). The dataset based on the characters of adult male morphology showed high levels of homoplasy and yielded very incongruent and unstable phylogenetic results, which are very sensitive to changes in analytical parameters. In the preferred and most parsimonious phylogenetic hypothesis, the Pediciidae is the sister-group of all other Tipulomorpha sensu stricto. The results indicate the paraphyly of the Limoniidae with respect to the Cylindrotomidae and Tipulidae, which are considered sister-groups. The Limoniidae subfamilies Limnophilinae, Limoniinae and Chioneinae are considered non-monophyletic. The study allowed a reconstruction of the possible ground plan condition of selected features of the adult male morphology of crane flies. The genera/subgenera Epiphragma (Epiphragma), Acantholimnophila, Shannonomyia, Limnophila (Arctolimnophila), Eloeophila, Conosia, Polymera, Polymera (Polymerodes), Prionolabis, Eutonia, Phylidorea (Phylidorea), Metalimnophila, Gynoplistia (Cerozodia), Gynoplistia (Dirhipis), Nothophila, Pseudolimnophila (Pseudolimnophila), Pilaria and Ulomorpha are considered monophyletic, but in general are defined by combinations of very homoplastic character states. Two Temperate Gondwanan clades, (Tonnoirella + (Edwardsomyia + (Tinemyia + (Rhamphophila + (Nothophila))))) and ((Notholimnophila + Bergrothomyia) + (Mesolimnophila + (Chilelimnophila + Ctenolimnophila))) are recovered. The genera Limnophila, Neolimnomyia, Gynoplistia (sensu lato) and Hexatoma (sensu lato) are considered non-monophyletic. The systematic position and some morphological characters of ‘problematic’ taxa, such as Dactylolabis, Elephantomyia, Helius and Atarba are discussed on the light of the proposed phylogeny and the analysis of the characters. Character states are richly illustrated. A detailed study of the morphology of the male genitalia is made, and several genera and species have the morphology of the male genitalia illustrated for the first time.

Morphological and molecular evidence of a possible hybrid zone of Leptidea sinapis and L. reali (Lepidoptera: Pieridae)

Overlapping measurements in the length of the genitalia of Leptidea sinapis/reali collected in Slovenia triggered an investigation of a possible natural hybridization between these two well known sibling species of butterflies. Random polymorphic DNA (RAPD) was used to generate species specific markers and sequences of the cytochrome oxidase subunit one gene for determination of the progeny. RAPD's clustering and mitochondrial DNA (mtDNA) phylogeny were congruent with the taxonomic placement of specimens of both species, but slightly incongruent with the results of the analysis of genital morphology. Two specimens with L. reali genitalia measurements, but genetically belonging to L. sinapis, had species specific RAPD markers of both species indicating probable hybrid origin. All the specimens with genitalia of intermediate length were also genetically assigned to L. sinapis indicating a possible one way introgression as predicted from their genitalia morphology. Leptidea sinapis was found predominantly in xerothermic habitats in Slovenia, whereas L. reali was more of a generalist except in the sub-Mediterranean region where it is limited to humid meadows.

A new species and first stage associations in Crinitella (Ephemeroptera: Ephemerellidae: Ephemerellinae)

The alates of Crinitella coheri (Allen and Edmunds) are described for the first time, and morphological variability of the species is discussed. Male adults have penes with dorsal projections at the base of the gonopores and forceps with a relatively straight lateral profile. Crinitella coheri female alates and associated eggs have been misidentified as those of a Hyrtanella species. Crinitella coheri is reported from Vietnam for the first time. We describe C. lacuna, new species, based on male and female subimagoes and larvae, and the species is included in Crinitella on the basis of genitalia morphology. Alates of C. lacuna are distinguished from C. coheri by the presence of a prominent dorsal longitudinal stripe, and larvae are distinguished by having paired median spines on abdominal terga, mouthparts that are not greatly reduced, and gills 3 that are relatively larger than those of C. coheri. Crinitella lacuna is reported from India, Thailand and Vietnam. The structures of Crinitella and Hyrtanella gill cavities are different and do not represent a synapomorphy for the two genera.

Copulation behaviour ofGlossina pallidipes(Diptera: Muscidae) outside and inside the female, with a discussion of genitalic evolution

If species-specific male genitalia are courtship devices under sexual selection by cryptic female choice, then species-specific aspects of the morphology and behaviour of male genitalia should often function to stimulate the female during copulation. The morphology and behaviour of the complex, species-specific male genitalia of the tsetse fly, Glossina pallidipes Austen, were determined from both direct observations and dissections of flash-frozen copulating pairs; we found that some male genitalic traits probably function to stimulate the female, while others function to restrain her. The male clamps the ventral surface of the female's abdomen tightly with his powerful cerci. Clamping does not always result in intromission. Clamping bends the female's body wall and her internal reproductive tract sharply, posteriorly and dorsally, and pinches them tightly. The male performed sustained, complex, stereotyped, rhythmic squeezing movements with his cerci that were not necessary to mechanically restrain the female and appeared instead to have a stimulatory function. Six different groups of modified setae on and near the male's genitalia rub directly against particular sites on the female during squeezing. The designs of these setae correlate with the force with which they press on the female and the probable sensitivity of the female surfaces that they contact. As expected under the hypothesis that these structures are under sexual selection by female choice, several traits suspected to have stimulatory functions have diverged in G. pallidipes and its close relative, G. longipalpis. Additional male non-genitalic behaviour during copulation, redescribed more precisely than in previous publications, is also likely to have a courtship function. The elaborate copulatory courtship behaviour and male genitalia may provide the stimuli that previous studies showed to induce female ovulation and resistance to remating.

Notes on Falsocis Pic (Coleoptera: Tenebrionoidea: Ciidae), with the description of an endangered Brazilian species

The genus Falsocis Pic is redescribed based on F. opacus Pic and F. brasiliensis sp. nov. an endangered Brazilian species. A key to males of the species of Falsocis is provided, together with a description of the external morphology of adults and of the morphology of male genitalia of both species. In addition, the female genitalia of F. brasiliensis sp. nov. are described. Falsocis is included in the tribe Ciini, and its relationship with Acanthocis Miyatake and other Ciidae genera is discussed. Falsocis brasiliensis sp. nov. is known from only three Atlantic Forest remnants, all surrounded by urban areas, pastures or agriculture, and is probably one of the most endangered Brazilian ciids.