Redescription of Pseudanuretes chaetodontis Yamaguti, 1936 (Copepoda, Siphonostomatoida, Caligidae) and description of some of its developmental stages, with a discussion on sexually dimorphic features in the genus

Abstract Pseudanuretes chaetodontis Yamaguti, 1936 is redescribed based on both sexes, from specimens recovered from the branchial lamellae of Chaetodontoplus septentrionalis (Temminck & Schlegel, 1844) (Pisces, Pomacanthidae) in Japan. In addition, both sexes of copepodid V are described, as well as the free-living phase composed of two naupliar stages and the infective copepodid I stage, all reared from eggs, for the first time. Sexually dimorphic features found in the adult are discussed and it is pointed out herein that P. parvulus (Wilson, 1913) was described based on a copepodid V female specimen by that original author. Both sexes of the copepodid V exhibit sexually dimorphic features of the male type, i.e., in the maxilliped and in leg 5.

Download Full-text

Embryonic Onset of Sexually Dimorphic Heart Rates in the Viviparous Fish, Gambusia holbrooki

Biomedicines ◽

10.3390/biomedicines9020165 ◽

2021 ◽

Vol 9 (2) ◽

pp. 165

Author(s):

Seyed Ehsan Mousavi ◽

G. John Purser ◽

Jawahar G. Patil

Keyword(s):

Developmental Stages ◽

Sexually Dimorphic ◽

Gambusia Holbrooki ◽

Cardiovascular Development ◽

Heart Rates ◽

Viviparous Fish ◽

Climatic Impacts ◽

And Performance ◽

Heart Physiology ◽

First Time

In fish, little is known about sex-specific differences in physiology and performance of the heart and whether these differences manifest during development. Here for the first time, the sex-specific heart rates during embryogenesis of Gambusia holbrooki, from the onset of the heart rates (HRs) to just prior to parturition, was investigated using light cardiogram. The genetic sex of the embryos was post-verified using a sex-specific genetic marker. Results reveal that heart rates and resting time significantly increase (p < 0.05) with progressive embryonic development. Furthermore, both ventricular and atrial frequencies of female embryos were significantly higher (p < 0.05) than those of their male sibs at the corresponding developmental stages and remained so at all later developmental stages (p < 0.05). In concurrence, the heart rate and ventricular size of the adult females were also significantly (p < 0.05) higher and larger respectively than those of males. Collectively, the results suggest that the cardiac sex-dimorphism manifests as early as late-organogenesis and persists through adulthood in this species. These findings suggest that the cardiac measurements can be employed to non-invasively sex the developing embryos, well in advance of when their phenotypic sex is discernible. In addition, G. holbrooki could serve as a better model to study comparative vertebrate cardiovascular development as well as to investigate anthropogenic and climatic impacts on heart physiology of this species, that may be sex influenced.

Download Full-text

Redescription of five known species of Hatschekia Poche, 1902 (Copepoda, Siphonostomatoida, Hatschekiidae) parasitic on Japanese tetraodontiform fishes, with discussion on sexually dimorphic features in the genus

Crustaceana ◽

10.1163/15685403-00003819 ◽

2018 ◽

Vol 91 (9) ◽

pp. 1107-1132 ◽

Cited By ~ 1

Author(s):

Kunihiko Izawa

Keyword(s):

Sexually Dimorphic ◽

Dorsal Shield ◽

Free Living ◽

Caudal Ramus ◽

Larval Stages ◽

First Time

Abstract Five known species of Hatschekia Poche, 1902, parasitic on the branchial lamellae of Japanese tetraodontiform fishes, are redescribed. They are H. monacanthi Yamaguti, 1939, H. bibullae Uyeno & Nagasawa, 2010, H. kuroshioensis Uyeno & Nagasawa, 2010, H. ostracii Yamaguti, 1953, and H. legouili Nuñes-Ruivo, 1954. The males of H. bibullae and H. legouili, free-living larval stages of H. bibullae reared from eggs, the copepodid IV female of H. kuroshioensis, and both sexes of copepodids III-V of H. legouili are described for the first time. The antenna, the postantennal process, the length of the caudal ramus, and the ornamentation of the dorsal shield of the cephalothorax, if present, are sexually dimorphic within the genus. By showing these sexually dimorphic features of the male, it is inferred that both sexes of copepodid II-IV and copepodid V male, have attributes of the male.

Download Full-text

Dynamics of sex-biased gene expression over development in the stick insect Timema californicum

10.1101/2021.01.23.427895 ◽

2021 ◽

Author(s):

Jelisaveta Djordjevic ◽

Zoé Dumas ◽

Marc Robinson-Rechavi ◽

Tanja Schwander ◽

Darren James Parker

Keyword(s):

Gene Expression ◽

Sexual Dimorphism ◽

Developmental Stages ◽

Adult Stage ◽

Stick Insect ◽

Sexually Dimorphic ◽

Rna Seq ◽

Hemimetabolous Insect ◽

First Time ◽

Early Developmental

AbstractSexually dimorphic phenotypes are thought to arise primarily from sex-biased gene expression during development. Major changes in developmental strategies, such as the shift from hemimetabolous to holometabolous development, are therefore expected to have profound consequences for the dynamics of sex-biased gene expression. However, no studies have previously examined sex-biased gene expression over development in hemimetabolous insects, precluding comparisons between developmental strategies. Here we characterized sex-biased gene expression at three developmental stages in a hemimetabolous stick insect (Timema californicum): hatchlings, juveniles, and adults. As expected, the proportion of sex-biased genes gradually increased over development. Sex-biased genes identified at early developmental stages were generally consistently male- or female-biased at later stages, suggesting their importance in sexual differentiation. We then compared the dynamics of sex-biased gene expression over development in T. californicum to those of the holometabolous fly Drosophila melanogaster by reanalyzing publicly available RNA-seq data from third instar larval, pupal and adult stages. In D. melanogaster, sex-biased gene expression increases abruptly at the adult stage when morphological sexual dimorphism is manifested. This supports the prediction that sex-biased gene expression mirrors phenotypic sexual dimorphism. Our study details for the first time the dynamics of sex-biased gene expression over development in a hemimetabolous insect and suggests that these dynamics differ extensively between holometabolous and hemimetabolous species.

Download Full-text

Descriptions of the postembryonic developmental stages of Hatschekia bifurcata Yamaguti & Yamasu, 1959 (Copepoda, Siphonostomatoida, Hatschekiidae)

Crustaceana ◽

10.1163/15685403-00003445 ◽

2015 ◽

Vol 88 (6) ◽

pp. 709-725 ◽

Cited By ~ 4

Author(s):

Kunihiko Izawa

Keyword(s):

Adult Female ◽

Host Species ◽

Developmental Stages ◽

Growth Curves ◽

Diagnostic Feature ◽

Free Living ◽

New Host ◽

First Time ◽

Ventral Process ◽

New Host Species

A series of descriptions of postembryonic developmental stages of Hatschekia bifurcata Yamaguti & Yamasu, 1959 is presented based on free-living larvae reared from eggs detached from ovigerous females recovered from the branchial lamellae of Aulacocephalus temmincki Bleeker, 1855, as well as on copepodids I-VI from A. temmincki and Diploprion bifasciatum Cuvier, 1828 (Pisces, Perciformes, Serranidae). The number of naupliar stages preceding the infective copepodid I is three in this species as in H. multibarbatae Izawa, 2015. A diagnostic feature of the species, a hook-like ventral process on the fourth antennular segment of the female, is regarded as an enlarged seta and was found to appear after copepodid V. A correction in the previously given setation of leg 2 and a complemental description of the antennule of the adult female are made. The male of this species is herein described for the first time. The sexes become distinct at copepodid III, and then growth curves of both sexes diverge stage by stage, as in H. multibarbatae. Aulacocephalus temmincki is reported as a new host species for H. bifurcata.

Download Full-text

Probing the floral developmental stages, bisexuality and sex reversions in castor (Ricinus communis L.)

Scientific Reports ◽

10.1038/s41598-021-81781-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sujatha Thankeswaran Parvathy ◽

Amala Joseph Prabakaran ◽

Thadakamalla Jayakrishna

Keyword(s):

Developmental Stages ◽

Ricinus Communis ◽

Sex Expression ◽

Pistil Abortion ◽

Ricinus Communis L ◽

Sex Reversion ◽

Stage 4 ◽

Meristem Development ◽

Male Specific ◽

First Time

AbstractCastor (Ricinus communis L) is an ideal model species for sex mechanism studies in monoecious angiosperms, due to wide variations in sex expression. Sex reversion to monoecy in pistillate lines, along with labile sex expression, negatively influences hybrid seed purity. The study focuses on understanding the mechanisms of unisexual flower development, sex reversions and sex variations in castor, using various genotypes with distinct sex expression pattern. Male and female flowers had 8 and 12 developmental stages respectively, were morphologically similar till stage 4, with an intermediate bisexual state and were intermediate between type 1 and type 2 flowers. Pistil abortion was earlier than stamen inhibition. Sex alterations occurred at floral and inflorescence level. While sex-reversion was unidirectional towards maleness via bisexual stage, at high day temperatures (Tmax > 38 °C), femaleness was restored with subsequent drop in temperatures. Temperature existing for 2–3 weeks during floral meristem development, influences sexuality of the flower. We report for first time that unisexuality is preceded by bisexuality in castor flowers which alters with genotype and temperature, and sex reversions as well as high sexual polymorphisms in castor are due to alterations in floral developmental pathways. Differentially expressed (male-abundant or male-specific) genes Short chain dehydrogenase reductase 2a (SDR) and WUSCHEL are possibly involved in sex determination of castor.

Download Full-text

First Report of Echinococcus ortleppi in Free-Living Wild Boar (Sus scrofa) from Portugal

Microorganisms ◽

10.3390/microorganisms9061256 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1256

Author(s):

Teresa Letra Mateus ◽

Maria João Gargaté ◽

Anabela Vilares ◽

Idalina Ferreira ◽

Manuela Rodrigues ◽

...

Keyword(s):

Wild Boar ◽

Internal Transcribed Spacer ◽

Sus Scrofa ◽

One Health ◽

Control Strategies ◽

Free Living ◽

First Report ◽

Wildlife Reservoirs ◽

First Time ◽

Echinococcus Granulosus Sensu Lato

Cystic echinococcosis (CE) is a zoonosis that is prevalent worldwide. It is considered endemic in Portugal but few studies have been performed on Echinococcus granulosus sensu lato and their hosts. In this study, CE cysts are reported for the first time in a free-living wild boar (Sus scrofa) in Portugal. The presence of the metacestodes in the liver of the wild boar was identified by morphological features, microscopic examination and molecular analysis. The sequencing of part of the DNA nuclear ribosomal internal transcribed spacer-1 (ITS-1) region revealed a G5 genotype that presently corresponds to Echinococcus ortleppi. This is the first report of E. ortleppi in Portugal and to the best of the authors’ knowledge, in Europe. These results suggest that wild boar may be a host of CE, namely, crossing the livestock–wildlife interface, which has important public health implications. Wildlife reservoirs must be taken into account as CE hosts and surveillance of game as well as health education for hunters should be implemented using a One Health approach, with implementation of feasible and tailor-made control strategies, namely, proper elimination of byproducts in the field.

Download Full-text

Combining QTL Mapping and Gene Expression Analysis to Elucidate the Genetic Control of ‘Crumbly’ Fruit in Red Raspberry (Rubus idaeus L.)

Agronomy ◽

10.3390/agronomy11040794 ◽

2021 ◽

Vol 11 (4) ◽

pp. 794

Author(s):

Luca M. Scolari ◽

Robert D. Hancock ◽

Pete E. Hedley ◽

Jenny Morris ◽

Kay Smith ◽

...

Keyword(s):

Genetic Control ◽

Developmental Disorder ◽

Molecular Mechanisms ◽

Developmental Stages ◽

Microarray Experiment ◽

Rubus Idaeus ◽

Red Raspberry ◽

Genotype By Sequencing ◽

First Time ◽

Selection Of

‘Crumbly’ fruit is a developmental disorder in raspberry that results in malformed and unsaleable fruits. For the first time, we define two distinct crumbly phenotypes as part of this work. A consistent crumbly fruit phenotype affecting the majority of fruits every season, which we refer to as crumbly fruit disorder (CFD) and a second phenotype where symptoms vary across seasons as malformed fruit disorder (MFD). Here, segregation of crumbly fruit of the MFD phenotype was examined in a full-sib family and three QTL (Quantitative Trait Loci) were identified on a high density GbS (Genotype by Sequencing) linkage map. This included a new QTL and more accurate location of two previously identified QTLs. A microarray experiment using normal and crumbly fruit at three different developmental stages identified several genes that were differentially expressed between the crumbly and non-crumbly phenotypes within the three QTL. Analysis of gene function highlighted the importance of processes that compromise ovule fertilization as triggers of crumbly fruit. These candidate genes provided insights regarding the molecular mechanisms involved in the genetic control of crumbly fruit in red raspberry. This study will contribute to new breeding strategies and diagnostics through the selection of molecular markers associated with the crumbly trait.

Download Full-text

Identification, Expression and Evolution of Short-Chain Dehydrogenases/Reductases in Nile Tilapia (Oreochromis niloticus)

International Journal of Molecular Sciences ◽

10.3390/ijms22084201 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4201

Author(s):

Shuai Zhang ◽

Lang Xie ◽

Shuqing Zheng ◽

Baoyue Lu ◽

Wenjing Tao ◽

...

Keyword(s):

Transcriptome Analysis ◽

Tandem Duplication ◽

Developmental Stages ◽

Short Chain ◽

Sexually Dimorphic ◽

Physiological Processes ◽

Genome Wide ◽

Nile Tilapia Oreochromis Niloticus ◽

Tandem Duplications

The short-chain dehydrogenases/reductases (SDR) superfamily is involved in multiple physiological processes. In this study, genome-wide identification and comprehensive analysis of SDR superfamily were carried out in 29 animal species based on the latest genome databases. Overall, the number of SDR genes in animals increased with whole genome duplication (WGD), suggesting the expansion of SDRs during evolution, especially in 3R-WGD and polyploidization of teleosts. Phylogenetic analysis indicated that vertebrates SDRs were clustered into five categories: classical, extended, undefined, atypical, and complex. Moreover, tandem duplication of hpgd-a, rdh8b and dhrs13 was observed in teleosts analyzed. Additionally, tandem duplications of dhrs11-a, dhrs7a, hsd11b1b, and cbr1-a were observed in all cichlids analyzed, and tandem duplication of rdh10-b was observed in tilapiines. Transcriptome analysis of adult fish revealed that 93 SDRs were expressed in more than one tissue and 5 in one tissue only. Transcriptome analysis of gonads from different developmental stages showed that expression of 17 SDRs were sexually dimorphic with 11 higher in ovary and 6 higher in testis. The sexually dimorphic expressions of these SDRs were confirmed by in situ hybridization (ISH) and qPCR, indicating their possible roles in steroidogenesis and gonadal differentiation. Taken together, the identification and the expression data obtained in this study contribute to a better understanding of SDR superfamily evolution and functions in teleosts.

Download Full-text

Arthropods in the nests of lesser spotted eagle (Aquila pomarina)

Biologia ◽

10.2478/s11756-009-0148-x ◽

2009 ◽

Vol 64 (5) ◽

Cited By ~ 10

Author(s):

Ján Krištofík ◽

Peter Mašán ◽

Zbyšek Šustek ◽

Dušan Karaska

Keyword(s):

Trophic Group ◽

Trophic Groups ◽

Significant Component ◽

Free Living ◽

Parasitic Species ◽

Number Of Species ◽

Aquila Pomarina ◽

Investigation Period ◽

First Time

AbstractIn 2001–2007, altogether 57 nests of lesser spotted eagle were collected in the Orava region in northwestern Slovakia and four groups of arthropods were extracted from them. Richest in number of species and individuals were mites (23 species, 17,500 ind.), followed by beetles (12 species, 725 ind.), whereas pseudoscorpions were represented only by Pselaphochernes scorpioides (39 ind.) and fleas by Ceratophyllus garei (3 ind.). Unlike nests of other birds, free-living mites predominated in the nests fauna (83% of individuals), followed by nidicolous species with more or less free relationship to the nests, while parasitic species represented only a negligible part of the fauna. For the first time we observed phoresy of Nenteria pandioni, a specific and abundant mite in the eagles’ nests, on the nidicolous staphylinid Haploglossa puncticollis. The beetle fauna in the nests was much poorer than in nests of other birds. The predatory H. puncticollis was dominant in the nests (83%) and occurred continuously during the whole investigation period. Other beetles, even the widely distributed nidicols such as the histerid Gnathoncus buyssoni, were found rarely in nests. Predators were also the only abundant trophic group of beetles in the nests, while other trophic groups of beetles abundantly co-occur in nests of majority of other birds. The occurrence of all beetles was very unevenly distributed during the investigation period, but was positively correlated with occurrence of mites. The relatively low number of species and individuals of mites and beetles in the lesser spotted eagle nests resulted from their position on tree tops, at a height of 20–30 m and their quick drying out by sun and wind. It was also indicated by an enormously low number of species and individuals of mycetophagous beetles, which represent a significant component of the fauna in nests of other birds.

Download Full-text

Observing microscopic phases of lichen life cycles on transparent substrata placed in situ

The Lichenologist ◽

10.1017/s0024282905015070 ◽

2005 ◽

Vol 37 (5) ◽

pp. 373-382 ◽

Cited By ~ 27

Author(s):

William B. SANDERS

Keyword(s):

Life Cycle ◽

Developmental Stages ◽

Life Cycles ◽

Potential Significance ◽

Free Living ◽

Lichen Community ◽

One Year ◽

The One ◽

Observation Period

The utility of plastic cover slips as a substratum for in situ study of lichen developmental stages is further explored in a neotropical foliicolous lichen community and in a European temperate corticolous community. Twenty-one months after placement in the tropical forest, the cover slips bore foliicolous lichen thalli with several species producing characteristic ascocarps and ascospores, indicating the suitability of the substratum for completion of the life cycle of these lichens. On cover slips placed within the temperate corticolous community, lichen propagules anchored to the substratum with relatively short attachment hyphae but did not develop further within the one year observation period. Intimately intermixed microbial communities of short-celled, mainly pigmented fungi and chlorophyte algae developed upon the transparent substratum. Among the algae, Trebouxia cells, often in groups showing cell division and without associated lichenizing hyphae, were commonly observed. The potential significance of the free-living populations in the life cycle of Trebouxia and in those of Trebouxia-associated lichen fungi is discussed.

Download Full-text