First Report on Karyotypic, Morphometric and Meiotic Analysis of a Predatory Bombardier Beetle Pherosophus catoirai (Coleoptera: Carabidae) from Jammu region of Outer Himalayas, India

Chromosomal studies and manual karyotyping are the aged techniques for determining the identity of a species on evolutionary scale; however, these techniques are simple, reliable and inexpensive to authenticate the existence of a particular species. In the present work, the chromosome complement and meiotic processes of a predatory bombardier beetle Pherosophus catoirai were investigated. This species presented 2n=35 as diploid chromosome number and the chromosomal formula was found to be 12m+8sm+12st+X0. Sex mechanism was X0 type with metacentric X chromosome. Y chromosome was absent in this species. Karyotype revealed small chromosomes except X chromosome which is found to be largest in the spermatogonial metaphase stage. Meiotic stages were pachytene, diplotene, diakinesis and metaphase-I. Present study may find importance to analyse evolution of chromosomes in order Coleoptera particularly in family Carabidae.

Effects of the Sex Chromosome Complement, XX, XO, or XY, on the Transcriptome and Development of Mouse Oocytes During Follicular Growth

The sex chromosome complement, XX or XY, determines sexual differentiation of the gonadal primordium into a testis or an ovary, which in turn directs differentiation of the germ cells into sperm and oocytes, respectively, in eutherian mammals. When the X monosomy or XY sex reversal occurs, XO and XY females exhibit subfertility and infertility in the mouse on the C57BL/6J genetic background, suggesting that functional germ cell differentiation requires the proper sex chromosome complement. Using these mouse models, we asked how the sex chromosome complement affects gene transcription in the oocytes during follicular growth. An oocyte accumulates cytoplasmic components such as mRNAs and proteins during follicular growth to support subsequent meiotic progression, fertilization, and early embryonic development without de novo transcription. However, how gene transcription is regulated during oocyte growth is not well understood. Our results revealed that XY oocytes became abnormal in chromatin configuration, mitochondria distribution, and de novo transcription compared to XX or XO oocytes near the end of growth phase. Therefore, we compared transcriptomes by RNA-sequencing among the XX, XO, and XY oocytes of 50–60 µm in diameter, which were still morphologically comparable. The results showed that the X chromosome dosage limited the X-linked and autosomal gene transcript levels in XO oocytes whereas many genes were transcribed from the Y chromosome and made the transcriptome in XY oocytes closer to that in XX oocytes. We then compared the transcript levels of 3 X-linked, 3 Y-linked and 2 autosomal genes in the XX, XO, and XY oocytes during the entire growth phase as well as at the end of growth phase using quantitative RT-PCR. The results indicated that the transcript levels of most genes increased with oocyte growth while largely maintaining the X chromosome dosage dependence. Near the end of growth phase, however, transcript levels of some X-linked genes did not increase in XY oocytes as much as XX or XO oocytes, rendering their levels much lower than those in XX oocytes. Thus, XY oocytes established a distinct transcriptome at the end of growth phase, which may be associated with abnormal chromatin configuration and mitochondria distribution.

A new species of the genus Rhaphidosoma Amyot et Serville, 1843 (Heteroptera, Reduviidae), with data on its chromosome complement

A new species, Rhaphidosoma paganicumsp. nov. (Heteroptera: Reduviidae: Harpactorinae: Rhaphidosomatini), is described from the Dry Zone of Myanmar. It is the fifth species of Rhaphidosoma Amyot et Serville, 1843, known from the Oriental Region, and the first record of the genus for Myanmar and Indochina. The structure of the external and internal terminalia of the male and female is described and illustrated in detail. The completely inflated endosoma is described for the first time in reduviids. The complex structure of the ductus seminis is shown; it terminates with a voluminous seminal chamber which opens with a wide secondary gonopore and may be a place where spermatophores are formed. The new species is compared with all congeners from the Oriental Region and Western Asia. It is characterised by the absence of distinct tubercles on the abdominal tergites of the male, the presence only two long tubercles and small rounded ones on the abdominal tergites VII and VI, respectively, in the female, the presence of short fore wing vestiges which are completely hidden under longer fore wing vestiges, and other characters. In addition to the morphological description, an account is given of the male karyotype and the structure of testes of Rh. paganicumsp. nov. and another species of Harpactorinae, Polididus armatissimus Stål, 1859 (tribe Harpactorini). It was found that Rh. paganicumsp. nov. has a karyotype comprising 12 pairs of autosomes and a multiple sex chromosome system (2n♂=24A+X1X2X3Y), whereas P. armatissimus has a karyotype comprising five pairs of autosomes and a simple sex chromosome system (2n♂=10A+XY). The males of these species were found to have seven and nine follicles per testis, respectively. FISH mapping of 18S ribosomal DNA (major rDNA) revealed hybridisation signals on two of the four sex chromosomes (Y and one of the Xs) in Rh. paganicumsp. nov. and on the largest pair of autosomes in P. armatissimus. The presence of the canonical “insect” (TTAGG)n telomeric repeat was detected in the chromosomes of both species. This is the first application of FISH in the tribe Raphidosomatini and in the genus Polididus Stål, 1858.

Chromosome morphology and cytomolecular characteristics of the perennial rye cultivar ‘Kriszta’

The perennial Secale cereanum cultivar ‘Kriszta’ is an artificial hybrid of S. cereale and S. strictum ssp. anatolicum. From the cross between the wheat line Mv9kr1 and ‘Kriszta’, which aimed the transfer of beneficial traits from rye to wheat, numerous translocation lines have been produced. For the identification of the translocated chromosomes, the unambiguous differentiation between chromosome arms of ‘Kriszta’ is essential. The identification of its short chromosome arms using conventional FISH probes is easy, but because of their similar hybridization patterns, its long arms cannot be distinguished. The present study aimed to create the detailed karyotype of ‘Kriszta’, especially that of long arms, by both chromosome measurements and FISH using highly repetitive, as well as subtelomeric tandem repeat, and synthetic microsatellite DNA sequences. Our results indicate that the chromosome complement of ‘Kriszta’ is not a simple combination of the chromosomes of the parental rye species but is composed of rearranged chromosomes. It is also showed that an adequate pair-wise combination of the DNA sequences pSc119.2, pSc200, pSc250, and (AAC)5 makes it possible to identify any of the long arms of S. cereanum cv. Kriszta chromosomes. The future usability of the identified wheat- ‘Kriszta’ translocated chromosomes is also discussed.

Neopedies taimensis n. sp. of Brazilian Dichroplini (Orthoptera: Acrididae, Melanoplinae) from Rio Grande do Sul, Brazil

Neopedies taimensis n. sp. is described as a new species of grasshopper from the genus Neopedies Hebard, 1931 collected in Taim Ecological Station, State of Rio Grande do Sul, Brazil. This description is supported with photographs that detail the male and female external and internal morphological characteristics. The new species differs from the other species known by furculae developed and sclerotized, epiproct with two protuberances, cerci quadrangular indented and sclerotized, ancorae developed and lophi with posterior projections divergent. In addition, we present habitat notes, geographic distribution, key to the species of genus and chromosome complement. Chromosome analyses were performed using standard staining procedures, showing diploid number of 2n = 23, X0♂/24, XX♀ and the karyotype made up of exclusively acrocentric chromosomes.

The monoploid chromosome complement of reconstructed ancestral genomes in a phylogeny

Using RACCROCHE, a method for reconstructing gene content and order of ancestral chromosomes from a phylogeny of extant genomes represented by the gene orders on their chromosomes, we study the evolution of three orders of woody plants. The method retrieves the monoploid complement of each Ancestor in a phylogeny, consisting a complete set of distinct chromosomes, despite some of the extant genomes being recently or historically polyploidized. The three orders are the Sapindales, the Fagales and the Malvales. All of these are independently estimated to have ancestral monoploid number [Formula: see text].

A Karyological Study of Tenualosa Ilisha (Hamilton, 1822) From the Confluence of Padma and Meghna River of Bangladesh

Tenualosa ilisha (Hamilton, 1822), commonly known as Hilsha shad is a valuable and highly acceptable species in terms of their high flavored properties. Hilsha shad has striking morpho-genetical adaptation to heterogeneous habitats across their migratory routes. Cytogenetic analysis demonstrates the changes in chromosomes. But none was focused on the cytogenetic analysis of T. ilisha in Bangladesh. T. ilisha was found to possess 2n = 42 number of chromosomes along with a karyotype formula: 1M + 31m + 8sm + 2st using giemsa staining technique. The results demonstrated ‘diffuse type of interphase nuclei, co-existence of continuous type and interstitial type of prophase chromosomes respectively. No heteromorphic sex chromosomes were determined cytologically. The presence of diverse types of chromosomes based on centromeric position, gradual decrease in total haploid chromosome complement, mean centromeric asymmetry, coefficient of variation of chromosome length and Stebbins’s classification highlighted its asymmetry in karyotype with advance nature. Therefore, the elemental karyological data will offer information for the proper identification, cytotaxonomical classification, expanding productivity and preservation of genetic resources ofT. ilisha. Bangladesh J. Zool. 49 (2): 243-255, 2021

Allozyme and Other Aspects of Variation in the Genus Bulbinella in New Zealand

<p>This thesis examines some aspects of morphological, cytogenetic and allozyme variation in the six species of the genus Bulbinella in New Zealand. Because evidence was found suggesting that fragmentation and reduction of the habitat of some species of the study genus had occurred, aspects of the conservation status of Bulbinella were also investigated. Some of the morphological characters described and used by Moore (1964) to separate the species were employed in this study as well as other characters recorded by the author in actively glowing plants. Generally, the seven taxa could be successfully distinguished using selected morphological characters, although in some species or populations a range of morphological forms was observed. Increased human land use (mainly mining, farming and associated activities) has reduced some populations of Bulbinella to low numbers by destroying large areas of habitat. In some cases once vast areas of Bulbinella have been reduced to fragments or probably exterminated. The karyotypes of five of the seven taxa were determined and these were all consistent with published data. G-banding was achieved in only one slide from one plant. A total of four bands (restricted to two pairs of chromosomes) was observed in the entire chromosome complement of 14. Each band was located on a separate chromosome. Inflorescence material from 61 natural populations of Bulbinella in New Zealand was examined for enzyme activity using starch gel electrophoresis. Activity was detected for eight of a total of 43 enzyme stains. Three monomorphic and 11 polymorphic loci were resolved. While no completely fixed differences between all the taxa could be demonstrated, four almost fixed differences were found. In some instances where populations belonging to different species were not geographically separated by great distances (<50km) shared alleles between species were demonstrated, indicating that introgression had occurred and may still be taking place. Overall, the genetic distance (Nei 1978) within taxa was less than that between taxa. The dendrogram resulting from cluster analysis of Nei's unbiased genetic distances divided the genus into four groups, three of which corresponded to three currently recognised taxa. The other group contained the remaining four taxa. Although the component taxa of this cluster could be readily separated using morphological characters, they could not be distinguished using allozyme data. The endemic distribution of B. rossii (Campbell Island and Auckland Island Group) and fixed morphological differences justify its remaining a separate taxon. The formal raising of B. gibbsii var. gibbsii to a separate specific status is subject to the analysis of further samples of this taxon. B. angustifolia, B, talbotii, and B. gibbsii vat. balanifera also remain separate taxa, with B. gibbsii var. balanifera being raised to a separate specific status. B. modesta, which is genetically closely related to B. hookeri, becomes a sub-species of this taxon.</p>

Allozyme and Other Aspects of Variation in the Genus Bulbinella in New Zealand

<p>This thesis examines some aspects of morphological, cytogenetic and allozyme variation in the six species of the genus Bulbinella in New Zealand. Because evidence was found suggesting that fragmentation and reduction of the habitat of some species of the study genus had occurred, aspects of the conservation status of Bulbinella were also investigated. Some of the morphological characters described and used by Moore (1964) to separate the species were employed in this study as well as other characters recorded by the author in actively glowing plants. Generally, the seven taxa could be successfully distinguished using selected morphological characters, although in some species or populations a range of morphological forms was observed. Increased human land use (mainly mining, farming and associated activities) has reduced some populations of Bulbinella to low numbers by destroying large areas of habitat. In some cases once vast areas of Bulbinella have been reduced to fragments or probably exterminated. The karyotypes of five of the seven taxa were determined and these were all consistent with published data. G-banding was achieved in only one slide from one plant. A total of four bands (restricted to two pairs of chromosomes) was observed in the entire chromosome complement of 14. Each band was located on a separate chromosome. Inflorescence material from 61 natural populations of Bulbinella in New Zealand was examined for enzyme activity using starch gel electrophoresis. Activity was detected for eight of a total of 43 enzyme stains. Three monomorphic and 11 polymorphic loci were resolved. While no completely fixed differences between all the taxa could be demonstrated, four almost fixed differences were found. In some instances where populations belonging to different species were not geographically separated by great distances (<50km) shared alleles between species were demonstrated, indicating that introgression had occurred and may still be taking place. Overall, the genetic distance (Nei 1978) within taxa was less than that between taxa. The dendrogram resulting from cluster analysis of Nei's unbiased genetic distances divided the genus into four groups, three of which corresponded to three currently recognised taxa. The other group contained the remaining four taxa. Although the component taxa of this cluster could be readily separated using morphological characters, they could not be distinguished using allozyme data. The endemic distribution of B. rossii (Campbell Island and Auckland Island Group) and fixed morphological differences justify its remaining a separate taxon. The formal raising of B. gibbsii var. gibbsii to a separate specific status is subject to the analysis of further samples of this taxon. B. angustifolia, B, talbotii, and B. gibbsii vat. balanifera also remain separate taxa, with B. gibbsii var. balanifera being raised to a separate specific status. B. modesta, which is genetically closely related to B. hookeri, becomes a sub-species of this taxon.</p>

SEX DIFFERENCES IN BLOOD PRESSURE RESPONSE TO CONTINUOUS ANG II INFUSION: ARE ONLY SEX HORMONES TO BLAME?

To investigate the involvement of the sex chromosome complement (SCC), organizational and activational hormonal effects in changes in mean arterial pressure during acute Ang II infusion, we used gonadectomized (GDX) mice of the "four core genotypes" model, which dissociates the effect of gonadal sex and SCC, allowing comparisons of sexually dimorphic traits between XX and XY females as well as XX and XY males. Additionally, β-estradiol and testosterone propionate (2ug/g) were daily injected for 4 days to evaluate activational hormonal effects. Statistical analysis of the changes in mean arterial pressure revealed an interaction of SCC, organizational and activational hormonal effects during Ang II infusion {F(7,39=2,60 p<0.01)}. Our results indicate that, in absence of activational hormonal effects, interaction between the SCC and organizational hormonal action differentially modulates changes in arterial pressure. In GDX mice without hormone replacement, Ang II infusion resulted in an increase in mean arterial pressure in XX-male, XX-female and XY-female mice, while no changes were observed in XY-male mice. Furthermore, β-estradiol replacement (GDX+E2 group) resulted in a decrease in blood pressure in XX-males, XX-females and XY-females (indicating an activational β-estradiol effect), while no changes were observed in the XY-male group. Moreover, testosterone propionate replacement (GDX+TP group) showed a greater increase in blood pressure in XY-male mice than in XX-males and XX-females, demonstrating an activational hormonal effect of testosterone in XY-male mice. Our data isolates and highlights the contribution and interaction of SCC, activational and organizational hormonal effects in sex differences in Ang II blood pressure regulation.