Parthenogenetic Populations Research Articles

POPULATIONS OF ARTEMIA CRUSTACEANS OF KARABASSKY FLOODS OF PRIBALKHASHYE

The article presents the analysis of biological parameters of parthenogenetics of Artemia crustaceans of the hypergaline reservoirs of Kazakhstan. In the lakes under study there are shown the changes of the total crustacean biomass decreasing from high-productive to low-productive. Most of the reservoirs with Artemia in Kazakhstan are characterized by the presence of Artemia parthenogenetic populations with the absence or extremely small presence of males. The aggregation of males in significant numbers may indicate the tension of the ecological situation in the reservoirs and the desire of the population to increase the survival and stability of the offspring. It has been stated that all age periods of crustacean maturation are found in the reservoirs. At the same time, the basis of Artemia populations in all studied lakes are the youngest stages - nauplius, which form 53-86% of the total number of Artemias. In lakes Artemia crustaceans are presented by bisexual parthenogenetic race, with all age stages of development during the summer - autumnal period of observations. The hydrochemical mode of hypergaline lakes of Karabassky floods is favorable for activity of Artemia Branchiopoda crustaceans. The size of crustacean biomass populations in Lake Balhash change on seasons ranging from low to very high. Lake No. 1 is highly productive in Artemias in the summer, and lake No. 2 - in the spring. Such difference in temporary aspect is caused by existence of various generations in the populations of the crustaceans on seasons. The data obtained prove the high potential of the studied small reservoirs of the Balkhash region in relation to autumn plankton cysts

Geographical parthenogenesis in the brown alga Scytosiphon lomentaria (Scytosiphonaceae): Sexuals in warm waters and parthenogens in cold waters.

Geographical parthenogenesis, a phenomenon where parthenogens and their close sexual relatives inhabit distinct geographical areas, has been considered an interesting topic in evolutionary biology. Reports of geographical parthenogenesis from land and freshwater are numerous, but this occurrence has been rarely reported from the sea. Brown algae are mostly marine and are thought to include numerous obligate parthenogens; still, little is known about the distribution, origin and evolution of parthenogens in this group. Here we report a novel pattern of geographical parthenogenesis in the isogamous brown alga Scytosiphon lomentaria. Sex ratio investigation demonstrated that, in Japan, sexual populations grew in the coast along warm ocean currents, whereas female-dominant parthenogenetic populations grew mainly in the coast along a cold ocean current. In the two localities where sexual and parthenogenetic populations were parapatric, parthenogens grew in more wave-exposed areas than sexuals. Population genetic and phylogenetic analyses, including those based on genome-wide single nucleotide polymorphism data, indicated that parthenogens have initially evolved at least twice and subsequent hybridizations between the parthenogens and sexuals have generated multiple new parthenogenetic lineages. The origin of the initial parthenogens is not clear, except that it would not be interspecies hybridization. Interestingly, we found that the production of sex pheromones, which attract male gametes, has been independently lost in the initial two parthenogenetic lineages. This parallel loss of the sexual trait may represent the direct origin of parthenogens, or the regressive evolution of a useless trait under asexuality.

Внутри- и межпопуляционная изменчивость цист и взрослых стадий артемии (Branchiopoda: Anostraca) в сибирских популяциях (морфометрия)

Размеры цист артемии являются важным показателем ценности их как кормового ресурса и в некоторой степени позволяют идентифицировать популяции. В статье проанализированы показатели цист артемии партеногенетических популяций (диаметр, толщина хориона, наличие пятен на оболочке), отобранных в гипергалинных озёрах Западной Сибири в разные годы, и морфометрические показатели рачков, выращенных из цист при одинаковой солёности. Установлена значительная внутри- и межпопуляционная изменчивость рассмотренных показателей. Абсолютные значения диаметра цист находились в пределах 210–330 мкм, средние значения по пробам — 243,5–282,9 мкм, средние по популяциям — 257,8–279,6 мкм; абсолютные значения диаметра декапсулированных цист — в пределах 196–294 мкм, средние значения по пробам — 236,5–262,6 мкм, средние по популяциям — 239,9–253,2 мкм; абсолютные значения толщины хориона цист — 3,3–16,9 мкм, средние значения по популяциям — 6,6–12,4 мкм. В основных промысловых озёрах, на которые приходится около 70 % от всего вылова цист артемии в России, цисты имели близкие среднепопуляционные размеры (262–268 мкм). Дано заключение об отсутствии внутрипопуляционной закреплённости таких признаков, как диаметр цист и толщина хориона, то есть они не могут служить надёжными показателями, идентифицирующими сибирские популяции. Установлена статистически значимая связь (r = −0,5) между солёностью материнского водоёма и диаметром эмбрионов артемии. Пятнистость цист, не превышающая 5 % почти во всех их пробах, у цист озера Кучукское составила 24 %. Анализ морфометрических показателей рачков, выращенных из цист, показал, что средняя длина рачков (9,27–11,63 мм), ширина абдомена (0,53–0,69 мм) и расстояние между глазами (1,36–1,52 мм) тесно коррелировали с солёностью материнского водоёма (значения r составили −0,76; −0,62; −0,67 соответственно). Кластерный анализ совокупности морфометрических признаков рачков указывает на объединение популяций по признаку солёности.

Dependence of egg hatching on Wolbachia density in a parthenogenetic weevil revealed by antibiotic treatment

AbstractNaupactini is a tribe of Neotropical broad‐nosed weevils highly diverse in South America. This group includes several parthenogenetic species, some of them harmful for agriculture and invasive around the world. Although some hypotheses based on polyploidy and hybridization have been proposed to explain the origin of parthenogenesis in weevils, the infection with the bacterium Wolbachia pipientis may be involved in the origin of parthenogenetic reproduction of some species. In this contribution, we studied the role of Wolbachia in the reproductive biology of Pantomorus postfasciatus Hustache (Coleoptera: Curculionidae) through a curing experiment using tetracycline. This weevil has a mixed mode of reproduction including sexual and parthenogenetic populations. Exposure to an antibiotic did not affect fecundity, but did reduce egg hatching in comparison with untreated individuals. Consequently, we inferred that Wolbachia most probably takes part in the reproduction of P. postfasciatus, either by exerting nutritive functions in oogenesis necessary for egg hatching, or by induction of thelytokous parthenogenesis. Although infection was not totally cured, Wolbachia load was significantly lower in treated than in control females. Thereby, we hypothesize that a minimum threshold density of Wolbachia is required for weevil reproduction. We conclude that all analyses support a role of Wolbachia in P. postfasciatus reproduction.

Reanalysis and Revision of the Complete Mitochondrial Genome of Artemia urmiana Günther, 1899 (Crustacea: Anostraca)

In the previously published mitochondrial genome sequence of Artemia urmiana (NC_021382 [JQ975176]), the taxonomic status of the examined Artemia had not been determined, due to parthenogenetic populations coexisting with A. urmiana in Urmia Lake. Additionally, NC_021382 [JQ975176] has been obtained with pooled cysts of Artemia (0.25 g cysts consists of 20,000–25,000 cysts), not a single specimen. With regard to coexisting populations in Urmia Lake, and intra- and inter-specific variations in the pooled samples, NC_021382 [JQ975176] cannot be recommended as a valid sequence and any attempt to attribute it to A. urmiana or a parthenogenetic population is unreasonable. With the aid of next-generation sequencing methods, we characterized and assembled a complete mitochondrial genome of A. urmiana with defined taxonomic status. Our results reveal that in the previously published mitogenome (NC_021382 [JQ975176]), tRNA-Phe has been erroneously attributed to the heavy strand but it is encoded in the light strand. There was a major problem in the position of the ND5. It was extended over the tRNA-Phe, which is biologically incorrect. We have also identified a partial nucleotide sequence of 311 bp that was probably erroneously duplicated in the assembly of the control region of NC_021382 [JQ975176], which enlarges the control region length by 16%. This partial sequence could not be recognized in our assembled mitogenome as well as in 48 further examined specimens of A. urmiana. Although, only COX1 and 16S genes have been widely used for phylogenetic studies in Artemia, our findings reveal substantial differences in the nucleotide composition of some other genes (including ATP8, ATP6, ND3, ND6, ND1 and COX3) among Artemia species. It is suggested that these markers should be included in future phylogenetic studies.

Evidence of parthenogenetic populations from the Paratanytarsus laccophilus species group (Diptera: Chironomidae) in the Alaskan Arctic

Parthenogenesis, reproduction without fertilization, is not common in the Chironomidae (Diptera), a family of insects with more than 6,000 described species. Nonetheless, parthenogenetic species and strains have been documented in at least three subfamilies (the Chironominae, Orthocladiinae, and Telmatogoninae), spanning 17 genera and ~30 species. One such species, Paratanytarsus laccophilus Edwards 1929, is known to be parthenogenetic in a small portion of its range in Finland, with most other European populations of this species showing evidence of sexual reproduction. We present evidence of parthenogenetic populations from the Paratanytarsus laccophilus species group in the Nearctic, specifically a High Arctic site near Utqiaġvik (formerly Barrow), Alaska. During May-July of 2015 and 2016, we sampled emerging adult chironomids and pupal exuviae daily to document insect emergence phenologies. Across 15 local populations, all 623 pupal exuviae collected from the P. laccophilus species group were female. Larvae reared from two populations under controlled temperature treatments emerged as female adults (N=37). When isolated, these reared female adults oviposited, and eggs hatched successfully. These progeny were reared for another 12-13 days, reaching second instar larvae when they were preserved at the end of our field season. Taken together, this evidence strongly indicates parthenogenesis from the P. laccophilus species group at this location. This species was not previously documented at Utqiaġvik. Although parthenogenetic, their emergence at this location was highly synchronized. In the harsh environment of arctic Alaska, the fitness rewards of parthenogenesis are likely great. Indeed, chironomid parthenogenesis in the northern hemisphere is most commonly documented from far-northern extremes and in extreme habitats.

Morphometric studies of artemia males from different populations of the Altai region

The long-term data from morphometric studies of Artemia males from bisexual and parthenogenetic populations from hyperhaline reservoirs of the Altai region (Bolshoe Yarovoe Lake, Maloe Shklo Lake, and the Tanatar Lakes system) is analyzed in this paper. The description of signs of sexual dimorphism and sexual structure in different populations is given. The influence of brine salinity and hydrogen index on morphometric parameters of males was analyzed. There are differences in the sexual structure of the Artemia population: in the lakes Maloe Shklo and the thanatar system, the populations are bisexual (the share of males is 28.5 — 75.0 %), in the lake Bolshoe yarovoe — parthenogenetic (the share of males on average does not exceed 3 %). At the same time, sexual dimorphism is typical for both types of populations: females are larger than males, males have a larger head (the distance between the eyes is greater by 15.5 %, the diameter of the eye is 26.1 %, the length of the antenna is 22.3 %) and a larger number of bristles (36.1 %). The greatest variability is observed in the parameters of the Furka structure associated with the salinity of water by feedback and the pH — line indicator. Significant differences between the samples of males were revealed. The largest number of significant differences in morphometric indicators was found between samples of males from bisexual populations (lake thanatar and lake Maloe Shklo), the smallest — between males from the parthenogenetic population of lake Bolshoe yarovoe and males from lake Maloe Shklo.

The first chromosomal analysis of bisexual populations of the Brazilian scorpion Tityus serrulatus (Scorpiones: Buthidae)

The scorpion Tityus serrulatus Lutz & Mello, 1922 (Buthidae) is endemic to Brazil and is considered the most toxic South American scorpion species. The ample distribution of this species and its occurrence in urban areas has been attributed primarily to the parthenogenetic mode of reproduction. For a long time, only all-female T. serrulatus populations were known. Male specimens are very rare and have been recently discovered in natural environments within the Brazilian semi-arid zone. In the present study, we investigated cytogenetically bisexual populations of T. serrulatus, and compared the data with those available for parthenogenetic specimens. The diploid number (2n=12) and the general configuration of the chromosomes in male and female specimens were similar to those recorded for parthenogenetic populations. Male postpachytene cells contained chromosomes in a parallel arrangement with no differentiation of the bivalents, indicating the absence of heteromorphic sex chromosomes. However, the number of 28S rDNA sites varied between male and female specimens. Females invariably presented only one rDNA cistron, while all the males had two. This finding seems to indicate the existence of a sex-specific heteromorphism in T. serrulatus, in which the females are heterogametic and the males are the homogametic sex.

Морфометрические исследования самцов артемии из разных популяций гипергалинных водоемов Алтайского края

The long-term data from morphometric studies of brine shrimp males from bisexual and parthenogenetic populations from hyperhaline reservoirs of the Altai region (Bolshoe Yarovoe Lake, Maloe Shklo Lake, and the Tanatar Lakes system) is analyzed in the paper. The description of signs of sexual dimorphism and sexual structure in different populations is given. The influence of brine salinity and hydrogen index on morphometric parameters of males is analyzed. Significant differences and similarities between samples of males were established.

Using ISSR Genomic Fingerprinting to Study the Genetic Differentiation of Artemia Leach, 1819 (Crustacea: Anostraca) from Iran and Neighbor Regions with the Focus on the Invasive American Artemia franciscana

Due to the rapid developments in the aquaculture industry, Artemia franciscana, originally an American species, has been introduced to Eurasia, Africa and Australia. In the present study, we used a partial sequence of the mitochondrial DNA Cytochrome Oxidase subunit I (mt-DNA COI) gene and genomic fingerprinting by Inter-Simple Sequence Repeats (ISSRs) to determine the genetic variability and population structure of Artemia populations (indigenous and introduced) from 14 different geographical locations in Western Asia. Based on the haplotype spanning network, Artemia urmiana has exhibited higher genetic variation than native parthenogenetic populations. Although A. urmiana represented a completely private haplotype distribution, no apparent genetic structure was recognized among the native parthenogenetic and invasive A. franciscana populations. Our ISSR findings have documented that despite that invasive populations have lower variation than the source population in Great Salt Lake (Utah, USA), they have significantly revealed higher genetic variability compared to the native populations in Western Asia. According to the ISSR results, the native populations were not fully differentiated by the PCoA analysis, but the exotic A. franciscana populations were geographically divided into four genetic groups. We believe that during the colonization, invasive populations have experienced substantial genetic divergences, under new ecological conditions in the non-indigenous regions.

Investigation of three enzymes and their roles in the embryonic development of parthenogenetic Haemaphysalis longicornis

BackgroundThe tick Haemaphysalis longicornis exhibits two separate reproductive populations: bisexual and parthenogenetic, which have diploid and triploid karyotypes, respectively. The parthenogenetic population can undergo engorgement without copulation and produce viable female-only offspring with a longer incubation period than the bisexual population. Three enzymes, cathepsin B, cathepsin D and acid phosphatase, were found to be involved in vitellin degradation during the embryonic development of bisexual H. longicornis. However, the expression and activity profiles of these enzymes during the embryonic development of parthenogenetic ticks remain unknown. In the present study, the transcriptional expression profile, enzyme activity and roles in embryogenesis of the three enzymes during the embryonic development of parthenogenetic H. longicornis were investigated.MethodsQuantitative real-time polymerase chain reaction (qPCR) and fluorescence detection were used to analyze the dynamic changes in the three enzymes during embryogenesis. The roles of the three enzymes during embryogenesis were also explored using RNA interference (RNAi).ResultsThe three enzymes were all expressed during embryonic development in parthenogenetic H. longicornis. The expression of cathepsin B was highest on day 15, whereas that of cathepsin D was highest on day 3 and the peak of acid phosphatase expression occurred on day 9. The activity of cathepsin B was highest on day 3 and lowest on day 5, then gradually increased and remained stable. Cathepsin D activity was highest on day 1 and showed a gradually decreasing trend, whereas acid phosphatase showed the opposite trend and reached a peak on day 23. RNA interference experiments in engorged female ticks revealed that there was no significant difference in the number of eggs laid, but the hatching rate of the eggs was significantly decreased.ConclusionThe three enzymes all play important roles in embryonic development of H. longicornis, but the expression patterns and changes in the activity of the enzymes in the bisexual and parthenogenetic populations are different. The results will help a better understanding of the similarities and differences underlying embryonic development in the bisexual and parthenogenetic populations and contribute to the future exploration of the development of the parthenogenetic population of H. longicornis.

An overview on the nomenclatural and phylogenetic problems of native Asian brine shrimps of the genus Artemia Leach, 1819 (Crustacea, Anostraca).

The genus Artemia Leach, 1819 is a cosmopolitan halophilic crustacean, consisting of bisexual species and obligate parthenogenetic populations. Asia is rich in Artemia biodiversity. More than 530 Artemia sites have been recorded from this area and more than 20 species/subspecies/variety names have been used for them. There exist various problems in the nomenclature, identification, and phylogenetic status of Artemia native to Asia, which are discussed in this paper.

Ant-mediated anholocyclic overwintering of Prociphilus fraxini (Hemiptera: Aphididae) in Central Europe

The first observations of the aphid Prociphilus fraxini (Fabricius, 1777) being involved in a mutualistic relationship with the ant Prenolepis nitens (Mayr, 1853) in Europe is documented. Mutualism of an aphid generation living with the ants Prenolepis nitens and Lasius brunneus (Latreille, 1798) is discussed in reference to the possible development of an overwintering parthenogenetic population of the aphid, persisting on the roots of its secondary host, Picea abies, due to coevolution of the aphid with ants.

Morphological description and DNA barcodes of adult males of Tanytarsus heliomesonyctios Langton, 1999 (Diptera, Chironomidae) in northeast of Russia.

An illustrated morphological description of the adult males of Tanytarsus heliomesonyctios Langton, 1999, is provided for the first time. The males were found in mountain lakes Bolshoi Darpir (Momsky District of the Republic of Sakha (Yakutia)) and Momontai (Susumansky District of the Magadan Region), located in the Kolyma River basin. Females, pupae and larvae of T. heliomesonyctios was previously described from Spitsbergen, Jan Mayen (Norway) and Ellesmere Island (Arctic Canada), and considered parthenogenetic. Tanytarsus heliomesonyctios is here for the first time noted for the fauna of Russia. Comparison of DNA barcodes shows high K2P nucleotide distances (1.7%) between the sexual populations (Norway and Russia) and the parthenogenetic populations (Svalbard and Canada). In the Bayesian tree, the COI- sequences from adult males group as sister to a strongly supported clade of sequences from parthenogenetic populations. This apparently indicates a single origin of parthenogeneticity, perhaps due to extreme environmental conditions.

Loss and gain of sexual reproduction in the same stick insect.

The outcome of competition between different reproductive strategies within a single species can be used to infer selective advantage of the winning strategy. Where multiple populations have independently lost or gained sexual reproduction it is possible to investigate whether the advantage is contingent on local conditions. In the New Zealand stick insect Clitarchus hookeri, three populations are distinguished by recent change in reproductive strategy and we determine their likely origins. One parthenogenetic population has established in the United Kingdom and we provide evidence that sexual reproduction has been lost in this population. We identify the sexual population from which the parthenogenetic population was derived, but show that the UK females have a post‐mating barrier to fertilisation. We also demonstrate that two sexual populations have recently arisen in New Zealand within the natural range of the mtDNA lineage that otherwise characterizes parthenogenesis in this species. We infer independent origins of males at these two locations using microsatellite genotypes. In one population, a mixture of local and nonlocal alleles suggested males were the result of invasion. Males in another population were most probably the result of loss of an X chromosome that produced a male phenotype in situ. Two successful switches in reproductive strategy suggest local competitive advantage for outcrossing over parthenogenetic reproduction. Clitarchus hookeri provides remarkable evidence of repeated and rapid changes in reproductive strategy, with competitive outcomes dependent on local conditions.

The Complete Mitochondrial Genome and Expression Profile of Mitochondrial Protein-Coding Genes in the Bisexual and Parthenogenetic Haemaphysalis longicornis.

The tick Haemaphysalis longicornis is widely distributed in eastern Asia, New Zealand and Australia, and is well-known as a vector of multiple zoonotic pathogens. This species exhibits two reproductive strategies, bisexual and obligate parthenogenetic reproduction. Hence, in the current study, the complete mitochondrial genomes of the bisexual and parthenogenetic populations were assembled and analyzed, and the expression of the mitochondrial protein-coding genes was evaluated and compared between the two reproductive populations. The results indicated that the length of the mitochondrial genomes of the two reproductive populations is 14,694 and 14,693 bp in the bisexual and parthenogenetic populations, respectively. The AT content in the mitochondrial genome of the bisexual and obligate parthenogenetic population reached 77.22 and 77.34%, respectively. The phylogenetic tree was constructed combining 13 protein-coding genes, which showed that the genetic distance between the bisexual and parthenogenetic populations was less than that between the subspecies. The expression of the mitochondrial protein-coding genes was quantitatively analyzed at different feeding status for the bisexual and parthenogenetic populations, and the results showed significant differences in the expression patterns of these genes, suggesting that they might trigger specific energy utilization mechanisms due to their different reproductive strategies and environmental pressures.

Parthenogenetic Females of the Stick Insect Clitarchus hookeri Maintain Sexual Traits.

The New Zealand stick insect Clitarchus hookeri has both sexual and parthenogenetic (all-female) populations. Sexual populations exhibit a scramble competition mating system with distinctive sex roles, where females are signalers and males are searchers, which may lead to differences in the chemical and morphological traits between sexes. Evidence from a range of insect species has shown a decay of sexual traits is common in parthenogenetic lineages, especially those traits related to mate attraction and location, presumably due to their high cost. However, in some cases, sexual traits remain functional, either due to the recent evolution of the parthenogenetic lineage, low cost of maintenance, or because there might be an advantage in maintaining them. We measured morphological and chemical traits of C. hookeri to identify differences between males and females and between females from sexual and parthenogenetic populations. We also tested the ability of males to discriminate between sexual and parthenogenetic females in a laboratory bioassay. Our results show that male C. hookeri has morphological traits that facilitate mobility (smaller body with disproportionately longer legs) and mate detection (disproportionately longer antennae), and adult females release significantly higher amounts of volatile organic compounds than males when this species is sexually active, in accordance with their distinctive sex roles. Although some differences were detected between sexual and parthenogenetic females, the latter appear to maintain copulatory behaviors and chemical signaling. Males were unable to distinguish between sexual and parthenogenetic females, suggesting that there has been little decay in the sexual traits in the parthenogenetic lineage of C. hookeri.

Ecological surveys on the parthenogenetic Artemia populations in the hypersaline lakes of Anatolia, Turkey

The objective of this study is to provide information on the parthenogenetic Artemia populations in some hypersaline lakes of Anatolia (Tuz, Bolluk, Tersakan, and Acıgöl). Sampling studies were performed for abiotic factors and population parameters between November 2009 and October 2010. During the survey we focused on the local Artemia populations to investigate population dynamics, reproduction, brood size, and cyst and naupliar biometrics. Generally, the Artemia habitats in Anatolia were relatively shallow, and thus they were subject to major seasonal fluctuations. Dramatic declines in population size in Tuz and Acıgöl Lakes were found during this study. All Artemia populations were parthenogenetic and brood sizes of females showed significant differences among the populations (P < 0.05). The largest brood size was observed in the Acıgöl population and it may be concluded that local conditions for reproductive success were more adequate in this population. Substantial differences among populations were revealed during the studies on cyst and naupliar biometry. Cyst diameter mean values ranged from 231.8 to 266.9 µm. The cyst diameters for the Acıgöl population are determined as the smallest in these populations and among the smallest values recorded in parthenogenetic populations. The total length of newly hatched nauplii ranged from 484 to 512 µm for these populations.

Rediscovery of Synemon selene (Lepidoptera: Castniidae) in the mid-north of South Australia

ABSTRACTKlug [J.C.F.] has been rediscovered in the mid-north of South Australia. The species was thought to be locally extinct from South Australia since 1948 when it was last seen flying by F.M. Angel and N.B. Tindale near Two Wells, 20 km north of Adelaide. We compared adult males and females from the mid-north population with S. selene from the type locality, and also to the parthenogenetic populations in western Victoria. We also compare the mtDNA (COI) gene for S. selene from South Australia to the parthenogenetic populations in Victoria and several other Synemon species.

Resolving two Haploembia (Embioptera: Oligotomidae) cryptic species: molecular data confirms parthenogenetic females can be distinguished by their antisocial behavior.

The names of two cryptic species of Haploembia found in California are resolved and methods for identification are summarized. Molecular data of the Histone III subunit was used to evaluate color and behavior as species identifiers, confirming that antisocial behavior is a good identifier for the parthenogenetic species (Haploembia tarsalis), whereas the more variable coloration patterns were helpful, but less so. A genome size ratio of 1.44 between the parthenogenetic H. tarsalis and the sexually reproducing H. solieri was observed, along with higher genetic variation within the asexual lineage. This, and the identification of what appears to be a putative hybrid, contributes to current work examining mutation rates and selective pressures on genome size in parthenogenetic populations.