Sexual Mode Research Articles

Nanopolystyrene beads affect motility and reproductive success of oyster spermatozoa (Crassostrea gigas)

Oysters are keystone species that use external fertilization as a sexual mode. The gametes are planktonic and face a wide range of stressors, including plastic litter. Nanoplastics are of increasing concern because their size allows pronounced interactions with biological membranes, making them a potential hazard to marine life. In the present study, oyster spermatozoa were exposed for 1 h to various doses (from 0.1 to 25 µg mL−1) of 50-nm polystyrene beads with amine (50-NH2 beads) or carboxyl (50-COOH beads) functions. Microscopy revealed adhesion of particles to the spermatozoa membranes, but no translocation of either particle type into cells. Nevertheless, the 50-NH2 beads at 10 µg mL−1 induced a high spermiotoxicity, characterized by a decrease in the percentage of motile spermatozoa (−79%) and in the velocity (−62%) compared to control spermatozoa, with an overall drop in embryogenesis success (−59%). This major reproduction failure could be linked to a homeostasis disruption in exposed spermatozoa. The 50-COOH beads hampered spermatozoa motility only when administered at 25 µg mL−1 and caused a decrease in the percentage of motile spermatozoa (−66%) and in the velocity (−38%), but did not affect embryogenesis success. Microscopy analyses indicated these effects were probably due to physical blockages by microscale aggregates formed by the 50-COOH beads in seawater. This toxicological study emphasizes that oyster spermatozoa are a useful and sensitive model for (i) deciphering the fine interactions underpinning nanoplastic toxicity and (ii) evaluating adverse effects of plastic nanoparticles on marine biota while waiting for their concentration to be known in the environment.

Age-dependent plasticity in reproductive investment, regeneration capacity and survival in a partially clonal animal (Hydra oligactis).

Asexual reproduction diversifies life-history priorities and is associated with unusual reproduction and somatic maintenance patterns, such as constant fertility with age, extensive regeneration ability and negligible senescence. While age-dependent plasticity in relative allocation to sexual versus asexual reproductive modes is relatively well studied, the modulation of somatic maintenance traits in parallel with age-dependent reproduction is much less well understood in clonal or partially clonal animals. Here, we asked how age-dependent investment into sexual and asexual reproduction co-varies with somatic maintenance such as regeneration in a partially clonal freshwater cnidarian Hydra oligactis, a species with remarkable regeneration abilities and experimentally inducible sex. We induced gametogenesis by lowering temperature at two ages, 1 or 4weeks after detachment from an asexual parent, in animals of a male and a female clone. Then we measured phenotypically asexual and sexual reproductive traits (budding rate, start day and number of sexual organs) together with head regeneration rate, survival and the cellular background of these traits (number of reproductive and interstitial stem cells) for 2 or 5months. Younger animals had higher asexual reproduction while individuals in the older group had more intensive gametogenesis and reproductive cell production. In parallel with these age-dependent reproductive differences, somatic maintenance of older individuals was also impacted: head regeneration, survival and interstitial stem cell numbers were reduced compared to younger polyps. Some of the traits investigated showed an ontogenetic effect, suggesting that age-dependent plasticity and a fixed ontogenetic response might both contribute to differences between age groups. We show that in H. oligactis asexual reproduction coupled with higher somatic maintenance is prioritized earlier in life, while sexual reproduction with higher maintenance costs occurs later if sex is induced. These findings confirm general life-history theory predictions on resource allocation between somatic maintenance and sexual reproduction applying in a partially clonal species. At the same time, our study also highlights the age-dependent integration of these resource allocation decisions with sexual/asexual strategies. Accounting for age-related differences might enhance repeatability of research done with clonal individuals derived from mass cultures.

An endophyte of Macrochloa tenacissima (esparto or needle grass) from Tunisia is a novel species in the Fusarium redolens species complex

ABSTRACT Here, we report on the morphological, molecular, and chemical characterization of a novel Fusarium species recovered from the roots and rhizosphere of Macrochloa tenacissima (halfa, esparto, or needle grass) in central Tunisia. Formally described here as F. spartum, this species is a member of the Fusarium redolens species complex but differs from the other two species within the complex, F. redolens and F. hostae, by its endophytic association with M. tenacissima and its genealogical exclusivity based on multilocus phylogenetic analyses. To assess their sexual reproductive mode, a polymerase chain reaction (PCR) assay was designed and used to screen the three strains of F. spartum, 51 of F. redolens, and 14 of F. hostae for mating type (MAT) idiomorph. Genetic architecture of the MAT locus in the former two species suggests that if they reproduce sexually, it is via obligate outcrossing. By comparison, results of the PCR assay indicated that 13/14 of the F. hostae strains possessed MAT1-1 and MAT1-2 idiomorphs and thus might be self-fertile or homothallic. However, when the F. hostae strains were selfed, 11 failed to produce perithecia and one only produced several small abortive perithecia. Cirrhi with ascospores, however, were only produced by 8/28 and 4/84 of the variable size perithecia, respectively, of F. hostae NRRL 29888 and 29890. The potential for the three F. redolens clade species to produce mycotoxins, pigments, and phytohormones was assessed by screening whole genome sequence data and by analyzing extracts on cracked maize kernel cultures via liquid chromatography–mass spectrometry.

Genetic patterns of the corals Euphyllia glabrescens and Lobophyllia corymbosa across the Indonesian Archipelago

Abstract. Jompa J, Umar W, Yusuf S, Tassakka ACM, Limmon GV, Rahmi, Putri AP, Halwi, Tamti H, Moore AM. 2020. Genetic patterns of the corals Euphyllia glabrescens and Lobophyllia corymbosa across the Indonesian Archipelago. Biodiversitas 21: xxxx. Scleractinian corals can reproduce in several ways, with two main sexual reproduction modes known as brooding and broadcast spawning. In this study, we described patterns of genetic variation within and connectivity between coral populations in western Indonesia (Seribu Archipelago), central Indonesia (Spermonde Archipelago), and eastern Indonesia (Ambon). We sampled two readily identifiable corals popular in the marine aquarium trade, one species widely reported as a brooder (Euphyllia glabrescens), the other as a broadcast spawner (Lobophyllia corymbosa). The mitochondrial COI genome was amplified for 117 samples. Within-population genetic variation was high, especially at the eastern Indonesia (Ambon) site. The genetic connectivity patterns were similar for the two corals, with high connectivity between the Seribu and Spermonde Archipelagos (despite a geographical separation of more than 1,000 km) and a lack of connectivity between these two sites and Ambon. These results indicate a potential barrier to gene flow between coral populations in western/central Indonesia and those to the east of Sulawesi Island.

Dominance of Mating Type A1 and Indication of Epigenetic Effects During Early Stages of Mating in Phytophthora infestans.

The potato late blight pathogen Phytophthora infestans has both an asexual and a sexual mode of reproduction. In Scandinavia, the pathogen is reproducing sexually on a regular basis, whereas clonal lineages dominate in other geographical regions. This study aimed at elucidating events or key genes underlying this difference in sexual behavior. First, the transcriptomes of eight strains, known as either clonal or sexual, were compared during early stages of mating. Principal component analysis (PCA) divided the samples in two clusters A and B and a clear grouping of the mating samples together with the A1 mating type parents was observed. Induction of genes encoding DNA adenine N6-methylation (6mA) methyl-transferases clearly showed a bias toward the cluster A. In contrast, the Avrblb2 effector gene family was highly induced in most of the mating samples and was associated with cluster B in the PCA, similarly to genes coding for acetyl-transferases, which play an important role in RXLR modification prior to secretion. Avrblb2 knock-down strains displayed a reduction in virulence and oospore formation, suggesting a role during the mating process. In conclusion, a number of gene candidates important for the reproductive processes were revealed. The results suggest a possible epigenetic influence and involvement of specific RXLR effectors in mating-related processes.

Ecology and distribution of ostracods in Mardin and Muş provinces in Turkey

A total of 78 taxa (58 spp) were found from 164 different aquatic sites in Mardin (65 sites) and Mus (99 sites) provinces during August 2013. Of them, 33 living species and 14 subfossils were found from 58 sites of Mardin, while 46 living and 15 subfossils were identified from 91 sites in Mus. All species were new records for both provinces. Bisexual populations of 13 species were reported. Vestalenula boteai, Hemicypris inversus, Hemicypris congenera, Cypretta hirsuta and bisexual populations of Trajancypris clavata and Psychrodromus robertsoni were reported for the first time from Turkey. Cypretta hirsuta was found for the first time out of its type region and locality. Now, the total numbers of bisexual ostracods in Turkey is increased up to 79 species. CCA explained 73.3% of relationships between species and environmental variables. Water temperature, pH and elevation were the most influential factors on species assemblages. Ecological tolerance and optimum estimates of individual species with different sexual mode showed fluctuations for different variables. Although elevation may play a deterministic role on species distribution, response to elevation can be species-specific, and related to several other environmental factors.

Morphogenetic characters of the model ciliate Euplotes vannus (Ciliophora, Spirotrichea): Notes on cortical pattern formation during conjugational and postconjugational reorganization

Ciliated protists represent a morphologically and genetically distinct group of single-celled eukaryotes which can reproduce asexually and sexually. Morphogenesis occurs in both asexual and sexual modes of reproduction which is of interest for researchers investigating cell differentiation, regeneration, systematics and evolution. However, studies of morphogenesis have concentrated almost entirely on the asexual mode. Here we use protargol staining to investigate the morphogenetic processes during sexual reproduction in the model species Euplotes vannus (Müller). The major events include: (1) two rounds of morphogenesis occur during sexual reproduction, i.e., conjugational and postconjugational reorganization; (2) in both processes the oral primordium is generated de novo in a pouch beneath the cortex; (3) the frontoventral-transverse cirri anlagen are formed de novo and fragment in a 3:3:3:3:2 pattern; (4) the leftmost cirrus and the paroral membrane do not change during conjugational morphogenesis, but reorganize de novo during postconjugational morphogenesis; (5) marginal cirral anlagen are formed de novo in both morphogenetic processes; (6) two or three caudal cirri are formed at the ends of the rightmost two or three old dorsal kineties; (7) the dorsal kineties are retained entirely. These results can serve as reference to investigate the morphogenetic events in the different stages of sexual reproduction.

Unlocking the Door of Boosting Biodirected Structures for High-Performance VN x O y /C by Controlling the Reproduction Mode.

Diverse reproduction modes of bio‐organisms open new intriguing opportunities for biochemistry‐enabled materials. Herein, a new strategy is developed to explore biodirected structures for functional materials via controlling the reproduction mode. Yeast with sexual or asexual reproduction mode are employed in this work. They result in two different biodirected structures, from bowl‐like hollow hemisphere to “bubble‐in‐sphere” (BIS) structure, for the VNxOy/C composites. Benefitting from the hierarchical structure, nanoscale particles and conductive biomass–derived carbon base, both VNxOy/C biocomposites achieve high power/energy density, good reliability, and excellent long‐term cycling stability in aqueous Zn‐ion batteries. Deep investigations further reveal that different biodirected structures greatly influence the electrochemical properties of biocomposites. The bowl‐like structures with thin shells and folded double layers achieve larger surface area and more active sites, which ensure their faster kinetics and better high rate capability. The BIS structures with a more compact assembly and higher stack capability are favorable to the better energy storage. Therefore, this work not only introduces a new clue to boost biodirected structures for functional materials, but also propels the development of Zn‐ion batteries in diverse applications.

Educação em saúde sobre infecções sexualmente transmissíveis para universitários de Enfermagem

Objective: To describe the experience of Nursing students in health education practices about sexually transmitted infections (STIs). Data Synthesis: The educational activities of an extension project were developed for first-year students at the Faculty of Nursing of the University of Para (UFPA), located in the municipality of Belem, Para, Brazil, from March to December 2019. The practice of health education was divided into three stages: STI: epidemiology, etiologic agent, symptoms and prevention; Good practices for the correct use of male and female condoms; and Sexual transmission mode of STIs / HIV and the importance of being health multipliers, which consisted of a dynamic and dialogue circle on the theme. Conclusion: The extension activity made it possible to discuss the promotion of students' sexual health aiming at the prevention and control of STI transmission. For extension workers, the experience favored the autonomy of health education activities and the understanding of the need to address the topic with young people entering the university and also to establish socialization with students to sensitize them to be health multipliers.

Fusarium xyrophilum, sp. nov., a member of the Fusarium fujikuroi species complex recovered from pseudoflowers on yellow-eyed grass (Xyris spp.) from Guyana

ABSTRACT We report on the discovery and characterization of a novel Fusarium species that produced yellow-orange pseudoflowers on Xyris spp. (yellow-eyed grass; Xyridaceae) growing in the savannas of the Pakaraima Mountains of western Guyana. The petaloid fungal structures produced on infected plants mimic host flowers in gross morphology. Molecular phylogenetic analyses of full-length RPB1 (RNA polymerase largest subunit), RPB2 (RNA polymerase second largest subunit), and TEF1 (elongation factor 1-α) DNA sequences mined from genome sequences resolved the fungus, described herein as F. xyrophilum, sp. nov., as sister to F. pseudocircinatum within the African clade of the F. fujikuroi species complex. Results of a polymerase chain reaction (PCR) assay for mating type idiomorph revealed that single-conidial isolates of F. xyrophilum had only one of the MAT idiomorphs (MAT1-1 or MAT1-2), which suggests that the fungus may have a heterothallic sexual reproductive mode. BLASTn searches of whole-genome sequence of three strains of F. xyrophilum indicated that it has the genetic potential to produce secondary metabolites, including phytohormones, pigments, and mycotoxins. However, a polyketide-derived pigment, 8-O-methylbostrycoidin, was the only metabolite detected in cracked maize kernel cultures. When grown on carnation leaf agar, F. xyrophilum is phenotypically distinct from other described Fusarium species in that it produces aseptate microconidia on erect indeterminate synnemata that are up to 2 mm tall and it does not produce multiseptate macroconidia.

Development of EST-SSR markers in Cenchrus ciliaris and their applicability in studying the genetic diversity and cross-species transferability

Most of the grasses of the genus Cenchrus (20-25 species) and Pennisetum (80-140 species) are distributed throughout the tropical and subtropical regions of the world and reproduce both by sexual and apomictic modes. However, the relationships among the Cenchrus-Pennisetum species are not very clear yet. Molecular markers like expressed sequence tag-simple sequence repeats (EST-SSRs) have been reported to be a better choice for resolving the phylogenetic relationships and to estimate the genetic diversity. The present study describes the identification of EST-SSR markers based on the transcriptome data of Cenchrus ciliaris inflorescence and illustrates the genetic diversity and phylogenetic relationships among these species. Of the 378 primer pairs used across 33 accessions of 21 Cenchrus, Pennisetum, and related grass (Bothriochloa, Dichanthium and Panicum) species, 116 EST-SSR markers were found to be polymorphic with an average polymorphism information content (PIC) of 0.49. Fifty-one EST-SSR loci and 520 alleles showed that where the PIC value is >0.5 there the GAG repeat motif was highly polymorphic. Two EST-SSR markers, CcSSR_80 and CcSSR_102, are polymorphic among the Cenchrus species, while they are absent in Pennisetum and the allied species. Five SSR markers (CcSSR_75, CcSSR_85, CcSSR_87, CcSSR_88 and CcSSR_114) showed 100% cross-transferability among the 21 Cenchrus-Pennisetum species. Species-specific alleles could also be detected for seven species of Cenchrus, Pennisetum and Panicum across 10 SSR markers. Assay of polymorphism across these agamic complexes showed that the three SSR markers (CcSSR_26, CcSSR_97 and CcSSR_109) were associated with Cenchrus-Pennisetum complex, and one (CcSSR_47) with Bothriochloa-Dichanthium complex. Markers with high discriminating power, namely CcSSR_4, CcSSR_38, CcSSR_48, CcSSR_66, CcSSR_67 and CcSSR_70, can be used to estimate the allelic sequence divergence across the sexual and apomictic lineages. Genetic diversity analysis using neighbour-joining (NJ) and principal co-ordinate analysis (PCoA) based approaches showed six and five clusters for the 33 accessions, respectively, having congruence in the pattern of clustering. These accessions were grouped according to their mode of reproduction. Cenchrus and Pennisetum species were grouped separately within the same clade, implying monophyletic group within a 'bristle clade'. Thus, this study showed high discrimination power of microsatellite (EST-SSR) markers to resolve the phylogenetic relationships.

Diversity analysis and trait association study for antioxidants and quality traits in landraces, farmers’ varieties and commercial varieties of Indian short day garlic (Allium sativum L.)

Garlic (Allium sativum L.) is the second most important Allium crop throughout the world, used raw, cooked, processed or an ingredient of traditional and modern medicine. It is one of the richest sources of total phenolics among the usually consumed vegetables. Indian garlic is indispensable item of globally famous and savoured traditional Indian cuisine. The genotypes grown are mostly short-day type, soft-neck with greater storage ability. Apart from dry bulbs, green garlic leaves are widely consumed in India. In the absence of sexual mode of reproduction, the development of new varieties is limited compared to other Alliums and breeding effort is focused on selection of elite clones from the available genetic resources. The aim of the present study was to (1) study the variations for antioxidants and antioxidant activities in leaf and clove samples of different accessions and (2) study the trait association and diversity in the collection for further selection. Antioxidant compounds were higher in cloves while green leaves were superior for antioxidant activity with variations in few lines. Commercial variety G-323 was found superior for leaf antioxidant activity and clove antioxidant content. Farmers’ variety scored higher for total soluble solids while breeding lines scored better for pungency. Total soluble solids and pungency mostly had negative association with antioxidant compounds and antioxidant activity. The diversity was independent of geographic region and status of selection (varieties, landraces and farmers’ varieties). The quality trait improvement effort should focus on medium TSS and pungent varieties for greater health benefits.

Bionomics and management of Scirtothrips dorsalis Hood (Insecta: Thysanoptera: Thripidae) on Camellia sinensis (L) O. Kuntze in tea plantations of north-eastern India

Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is a polyphagous and cosmopolitan pest. Its infestation on tea plant has increased considerably in the last few decades as a result of which it has now got established as one of the major sucking pests in the tea-growing areas of north-eastern (NE) India, and the rest of India at large. A number of factors, such as climate change, deforestation, over-reliance on pesticides, coupled with the capability of thrips to sustain and survive in monocultures, high reproductive rate both by parthenogenesis and sexual mode, short generation time, ability to survive as cryptic, quiescent prepupa and pupa and development of resistance to insecticides influence their periodical outbreaks. Tea thrips cause both direct and indirect damage to tea plants by feeding as well as egg laying in tender leaf tissues and buds causing stunted plant growth and significant yield loss. In this review, all available details pertaining to S. dorsalis infesting the tea plants have been summarised in the context of its management.

Evolution of sex ratio through gene loss

The maintenance of males at intermediate frequencies is an important evolutionary problem. Several species of Caenorhabditis nematodes have evolved a mating system in which selfing hermaphrodites and males coexist. While selfing produces XX hermaphrodites, cross-fertilization produces 50% XO male progeny. Thus, male mating success dictates the sex ratio. Here, we focus on the contribution of the male secreted short (mss) gene family to male mating success, sex ratio, and population growth. The mss family is essential for sperm competitiveness in gonochoristic species, but has been lost in parallel in androdioecious species. Using a transgene to restore mss function to the androdioecious Caenorhabditis briggsae, we examined how mating system and population subdivision influence the fitness of the mss+ genotype. Consistent with theoretical expectations, when mss+ and mss-null (i.e., wild type) genotypes compete, mss+ is positively selected in both mixed-mating and strictly outcrossing situations, though more strongly in the latter. Thus, while sexual mode alone affects the fitness of mss+, it is insufficient to explain its parallel loss. However, in genetically homogenous androdioecious populations, mss+ both increases male frequency and depresses population growth. We propose that the lack of inbreeding depression and the strong subdivision that characterize natural Caenorhabditis populations impose selection on sex ratio that makes loss of mss adaptive after self-fertility evolves.

PS-03-004 Sexual beliefs, modes and cognitive schemas in endometriosis women: A barrier in seeking help for sexual pain?

PS-03-004 Sexual beliefs, modes and cognitive schemas in endometriosis women: A barrier in seeking help for sexual pain?

Transcriptomic analysis reveals differences in the regulation of amino acid metabolism in asexual and sexual planarians

Many flatworms can alternate between asexual and sexual reproduction. This is a powerful reproductive strategy enabling them to benefit from the features of the two reproductive modes, namely, rapid multiplication and genetic shuffling. The two reproductive modes are enabled by the presence of pluripotent adult stem cells (neoblasts), by generating any type of tissue in the asexual mode, and producing and maintaining germ cells in the sexual mode. In the current study, RNA sequencing (RNA-seq) was used to compare the transcriptomes of two phenotypes of the planarian Dugesia ryukyuensis: an asexual OH strain and an experimentally sexualized OH strain. Pathway enrichment analysis revealed striking differences in amino acid metabolism in the two worm types. Further, the analysis identified serotonin as a new bioactive substance that induced the planarian ovary de novo in a postembryonic manner. These findings suggest that different metabolic states and physiological conditions evoked by sex-inducing substances likely modulate stem cell behavior, depending on their different function in the asexual and sexual reproductive modes. The combination of RNA-seq and a feeding assay in D. ryukyuensis is a powerful tool for studying the alternation of reproductive modes, disentangling the relationship between gene expression and chemical signaling molecules.

Transmission of Zika Virus Through the Rectal Route Leads to Mucosal and Systemic Infection with Reduced Neuropathology in Mice

Zika virus (ZIKV) is a mosquito‐borne flavivirus originally confined to Africa and Asia that has most recently spread to the Americas and the Caribbean. ZIKV circulates in sylvatic and urban transmission cycles and causes asymptomatic infection in most affected individuals, while the rest of the population experiences mild febrile syndrome. In some adults, ZIKV causes neurotropic Guillain–Barré syndrome. Vertical transmission of ZIKV in infected mothers causes fetal growth restriction, microcephaly, and congenital eye disease. There have been reports of infected individuals transmitting ZIKV sexually from male to female, male to male, and a suspected case of female to male. ZIKV has been detected in the semen of infected males months after symptom onset and thus, ZIKV persistence in the semen and testes can increase the risk of viral transmission for men having sex with men (MSM) and between heterosexual partners through rectal route. To further understand the risk of ZIKV acquisition through this route, we established a rectal route of infection model using immunocompromised (Ifnar1−/−) mice to investigate the sexual (rectal) and mosquito (subcutaneous) modes of transmission and their resulting systemic and mucosal responses to infection. Rectal inoculation of ZIKV results in viremia with non‐lethal infection, while establishing active rectal and testicular infection that persists for at least 21 days. We found that after one day of infection, ZIKV infects epithelial cells comprising the mucosal epithelium and dendritic cells within the lamina propria and submucosa. Significantly increased levels of the chemokine CCL2 and CD4+ T‐cell response were observed at 3 and 7 days post‐infection, respectively, relative to the subcutaneously infected group. Moreover, rectal route of infection results in reduced immune cell infiltration and inflammation in the brain with a robust CCL2 and CXCl10 response, while subcutaneous infection caused severe brain pathology and induces a more robust CD8+ T‐cell response. Lastly, at 21 days, the rectal group had specific anti‐ZIKV antiviral response suggesting the role of adaptive immune response in restricting lethal viral infection. Our studies provide comprehensive insight of ZIKV transmission through rectal route and the resulting reduced neuropathology and control of disease progression in mice due to early virological and immunological events following infection of the rectal mucosa.Support or Funding InformationThis research was funded by Cedars‐Sinai Medical Center's Institutional Research Award to V.A., the California Institute for Regenerative Medicine (CIRM) Quest – Discovery Stage Research Projects Grant (DISC2‐10188) to V.A. at UCLA, and the UCLA Interdisciplinary Postdoctoral Training Grant (T32) in Virology and Gene Therapy to L.E.M.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Perspectives on the clonal persistence of presumed \u2018ghost\u2019 genomes in unisexual or allopolyploid taxa arising via hybridization

Although hybridization between non-sibling species rarely results in viable or fertile offspring, it occasionally produces self-perpetuating or sexually-parasitic lineages in which ancestral genomes are inherited clonally and thus may persist as ‘ghost species’ after ancestor extinction. Ghost species have been detected in animals and plants, for polyploid and diploid organisms, and across clonal, semi-clonal, and even sexual reproductive modes. Here we use a detailed investigation of the evolutionary and taxonomic status of a newly-discovered, putative ghost lineage (HX) in the fish genus Hypseleotris to provide perspectives on several important issues not previously explored by other studies on ghost species, but relevant to ongoing discussions about their detection, conservation, and artificial re-creation. Our comprehensive genetic (allozymes, mtDNA) and genomic (SNPs) datasets successfully identified a threatened sexual population of HX in one tiny portion of the extensive distribution displayed by two hemi-clonal HX-containing lineages. We also discuss what confidence should be placed on any assertion that an ancestral species is actually extinct, and how to assess whether any putative sexual ancestor represents a pure remnant, as shown here, or a naturally-occurring resurrection via the crossing of compatible clones or hemi-clones.

Characterizing the transitioning epidemiology of herpes simplex virus type 1 in the USA: model-based predictions

BackgroundHerpes simplex virus type 1 (HSV-1) is a prevalent lifelong infection that appears to be undergoing an epidemiologic transition in the United States (US). Using an analytical approach, this study aimed to characterize HSV-1 transitioning epidemiology and estimate its epidemiologic indicators, past, present, and future.MethodsAn age-structured mathematical model was developed to describe HSV-1 transmission through oral and sexual modes of transmission. The model was fitted to the National Health and Nutrition Examination Surveys, 1976–2016 data series.ResultsHSV-1 seroprevalence was projected to decline from 61.5% in 1970 to 54.8% in 2018, 48.5% in 2050, and 42.0% in 2100. In < 3 decades, seroprevalence declined by > 30% for those aged 0–19 years, but < 5% for those aged > 60. Meanwhile, the number of new infections per year (oral and genital) was persistent at 2,762,000 in 1970, 2,941,000 in 2018, 2,933,000 in 2050, and 2,960,000 in 2100. Of this total, genital acquisitions contributed 252,000 infections in 1970, 410,000 in 2018, 478,000 in 2050, and 440,000 in 2100—a quarter of which are symptomatic with clinical manifestations. For those aged 15–49 years, nearly 25% of incident infections are genital. Most genital acquisitions (> 85%) were due to oral-to-genital transmission through oral sex, as opposed to genital-to-genital transmission through sexual intercourse.ConclusionHSV-1 epidemiology is undergoing a remarkable transition in the US, with less exposure in childhood and more in adulthood, and less oral but more genital acquisition. HSV-1 will persist as a widely prevalent infection, with ever-increasing genital disease burden.

Ileal pouch anal anastomosis in women of childbearing age: The impact of surgery upon sexual function, fertility, pregnancy, and mode of delivery

Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the mainstay of surgical management for medically refractory ulcerative colitis as well as familial adenomatous polyposis. These procedures are often performed on women of childbearing age and therefore have significant potential impact on future childbearing for these patients. Specifically, IPAA may result in variable changes in sexual function and a well-documented decrease in fertility, likely secondary to distortion of fallopian anatomy and adhesions after dissection. Knowledge of these aspects of IPAA are important for colorectal surgeons as they counsel patients preoperatively and for both colorectal surgeons and obstetricians as they advise their patients with IPAA post-operatively on matters related to sexual function, reproductive health, and delivery.