Chromosome relationships and meiotic mechanisms of certain morsitans group tsetse flies and their hybrids

There are three pairs of euchromatic components, the L₁ and L₂ autosomes and the X chromosome pair respectively, which are found in both G. austeni and the three forms of G. morsitans. Each species/sub-species also includes in its complement a group of heterochromatic autosomes (S) which have various morphologies and differ in number both within and between the species/sub-species. Several lines of evidence are outlined which point to these being supernumerary B chromosomes. Male meiosis is normally achiasmate and only L₁ and L₂ autosomes pair completely. X-Y association is restricted to a small pairing segment the position of which on the X is constant for all the species/sub-species. It is located in one of two positions on the Y chromosome according to the species/sub-species. The S chromosomes behave as hereditary univalents at first anaphase while the sex bivalent can undergo distance pairing best exemplified in G. austeni and G. submorsitans. A Y structural mutant line gives some indication of the size of the pairing segment and demonstrates that survival and maleness is possible even when two-thirds of the chromosome is missing. Meiotic and polytene chromosome studies connected with hybridisation experiments designed to test the sterility factor as a potential means of tsetse control assist in establishing the evolutionary relationship of the subspecies.     

Resolution of Phenotypically Distinct Strains of Enterococcus spp. in a Complex Microbial Community Using cpn60 Universal Target Sequencing

Characterization of complex microbial communities is frequently based on the examination of polymerase chain reaction amplified sequences from a single phylogenetic marker, usually the 16S rRNA gene. However, this commonly used target often does not offer robust resolution of species or sub-species and is thus not a sufficiently informative target for understanding microbial population dynamics occurring at the strain level. We have used the cpn60 universal target sequence to characterize Enterococcus isolates from feces of growing pigs and have shown that sub-species groups, not detected using 16S rRNA sequences, can be resolved. Furthermore, groups resolved by cpn60-based phylogenetic analysis have distinct phenotypes. We report changes in the structure and function of Enterococcus communities in pig feces sampled from individual animals at three times, from suckling through to maturity. Enterococcus faecalis was largely replaced by Enterococcus hirae between suckling and 9 weeks of age, and a shift from one sub-species group of E. hirae to another was observed in all animals between 9 and 15 weeks. Conversely, E. faecalis strains remained consistent throughout the study period. Our results demonstrate that cpn60 sequences can be used to detect strain level changes in Enterococcus populations during succession in the fecal microbiota of growing pigs.     

Differentiation of species of the Streptococcus bovis/equinus-complex by MALDI-TOF Mass Spectrometry in comparison to sodA sequence analyses

The Streptococcus bovis/equinus complex is a heterogeneous group within the group D streptococci with important clinical relevance regarding infective endocarditis, sepsis and colon carcinoma. The taxonomic identification of species and sub-species of this complex, by the standard methods remains difficult.In the present study, we compared the cluster analysis of 88 strains of species of the S. bovis/equinus complex by sequence analysis of the manganese-dependent superoxide dismutase gene (sodA) and by Matrix Assisted Laser Desorption/Ionization-Time Of Flight Mass Spectrometry (MALDI-TOF MS). We observed a high congruence of strain grouping by MALDI-TOF MS in comparison with sodA sequence analyses, demonstrating the accuracy and reliability of MALDI-TOF MS in comparison to DNA sequence-based method.By generating mass spectra for each species and sub-species, we were able to discriminate all members of the S. bovis/equinus complex. Furthermore, we demonstrated reliable identifications to the species level by MALDI-TOF MS, independently of cultivation conditions.     

Phylogenetic relationships among four species and a sub-species of Mullidae (Actinopterygii; Perciformes) based on mitochondrial cytochrome B, 12S rRNA and cytochrome oxidase II genes

DNA sequence comparisons of three mitochondrial DNA genes were used to reveal phylogenetic relationships among four species and a sub-species of Mullidae family. This is the first report using mitochondrial DNA sequence data to infer intraspecific relationship among different populations of Mullus barbatus and Mullus surmuletus; phylogenetic relationships between M. barbatus and its sub-species; M. barbatus ponticus. Cytochrome b, 12S ribosomal RNA, and cytochrome oxidase II regions of 242 individuals belonging to species M. barbatus, M. surmuletus, Upeneus moluccensis, Upeneus pori and sub-species M. barbatus ponticus were sequenced and phylogenetic trees were constructed using four different algorithms. The phylogenetic trees constructed support the existing taxonomical data of two mullid genera (Mullus, Upeneus). Molecular data shows no significant difference between same species of different geographical populations. The results suggest that the molecular difference is not large enough between M. barbatus and M. barbatus ponticus to consider them as sub-species.     

Ontogenetic changes in innate immune function in captive and wild subspecies of prairie-chickens (Tympanuchus cupido spp.)

The Attwater's prairie-chicken (Tympanuchus cupido attwateri), a federally endangered grouse species, is currently experiencing high chick mortality in wild populations and the causes are unknown. We tested 3 indicators of innate immunity (hemaggluttination, serum lysozyme, and total immunoglobulin [IgY] levels) in the Attwater's prairie-chicken and a closely related sub-species, the greater prairie-chicken (Tympanuchus cupido pinnatus). Agglutination titers were approximately 25% higher in the juvenile and adult Attwater's prairie-chickens compared to equivalently aged greater prairie-chickens. Additionally, total IgY levels in wild-collected Attwater's prairie-chicken egg samples were 34% higher than IgY levels in captive greater prairie-chickens or Attwater's prairie-chicken eggs. These results suggest that differences in innate immune function exist between these sub-species and also among Attwater's prairie-chicken subpopulations that are exposed to different environmental conditions. © 2012 The Wildlife Society.     

Isoprenoid quinone composition of representatives of the genus Campylobacter

The isoprenoid quinone composition of 17 strains representing nine species or sub-species of the genus Campylobacter was investigated. All strains produced similar respiratory quinone patterns consisting of unsaturated menaquinones with six isoprene units and a novel unidentified quinone. Mass spectral analysis indicate the unknown compound has six isoprene units and a formula C₄₂H₅₈O₂. The present study indicates respiratory quinones may be useful generic markers for Campylobacter.     

Studies on induced mutants with reference to species relationships in some tetraploid Triticums

Summary A mutational analysis of five tetraploid species of Triticum was carried out to study different types of systematic mutants. Rare systematic mutants viz., free-threshing mutants and the timopheevioid mutant of T. dicoccum, polonicum-type mutants of T. durum, turgidum-type mutants of T. carthlicum and durum-type mutants of T. turgidum and polonicum, which occurred with consistently high frequencies, are discussed in relation to the phylogenetical interrelationships of these species. The study supports Mac Key's (1966) proposal that all these species would be best grouped as sub-species of Triticum turgidum.A part of the Ph. D. Thesis submitted to Indian Agricultural Research Institute, New Delhi by M. V. R. Prasad under the Guidance of Dr. M. S. Swaminathan.     

The taxonomic relationships within the genus Excoecaria L. (Euphorbiaceae) based on leaf morphology and rDNA sequence data

The tropical Indo-Pacific genus Excoecaria L. (Euphorbiaceae) has several closely related species in Australia whose taxonomic relationships are unclear. The most widely reported species in Australia is the mangrove species Excoecaria agallocha L. (type species), whose taxonomic and geographic limits are difficult to define from its closely related species or sub-species. Two additional taxa have also been described but not clearly differentiated from the type species: Excoecaria dallachyana Baillon and Excoecaria ovalis Endl. This project aimed to determine the taxonomic relationships of the Australian Excoecaria species using both leaf morphological data and DNA sequence data from the internal transcribed spacer (ITS) region of ribosomal genes. The nucleotide differences in the examined ITS1 region show that E. agallocha from eastern Australia and E. ovalis from Western Australia respectively, are genetically uniform within species but differ from each other consistently, thus supporting species status. The leaf morphological data also support this view: single factor analysis of variance consistently separated E. ovalis from E. agallocha on the basis of leaf width, leaf length and length of petiole. In contrast, E. ovalis from the Gulf of Carpentaria differs only slightly from E. ovalis in Western Australia, but no evidence was found to suggest any leaf morphological differentiation within this species. The analysis also suggests that E. dallachyana is not closely related to either mangrove species E. agallocha or E. ovalis, despite superficial morphological similarities.     

Large and irregular population fluctuations in migratory Pacific (Calidris alpina pacifica) and Atlantic (C. a. hudsonica) dunlins are driven by density-dependence and climatic factors

Understanding the forces driving population dynamics is critical for species conservation and population management. For migratory birds, factors that regulate population abundance could come from effects experienced on breeding areas, wintering grounds, or during migration. We compiled survey data for Pacific and Atlantic subspecies of dunlins (Calidris alpina pacifica and C. a. hudsonica) from range-wide Christmas bird counts (1975–2010), and investigated the influences on this population index of density-dependence, falcon numbers, a set of seasonal environmental conditions during breeding, migration and non-breeding periods, and large-scale meteorological measures. For both sub-species, numbers fluctuated irregularly, varying threefold over the survey period, with no long-term upward or downward trend. Based on Royama's general model framework, the change in numbers between successive years for both sub-species was negatively affected by the total count in the previous year (i.e., negative density-dependence) and by the eastward component of storm movement during fall migration, with slower motion associated with higher population growth. The remaining environmental factors differed between the sub-species (snowmelt date on the Pacific, temperature on the Atlantic) or acted in opposite directions (soil moisture). The directional effects of each of these factors are consistent with the biology of dunlin, and together they explain 67.4 (72.9 %) of the variation in the rate of change of Pacific (Atlantic) dunlin annual counts. Falcon numbers were not predictive, despite a tenfold increase in abundance, suggesting compensatory mortality. This study highlights directions for future studies, and provides a model for the analysis of other migratory species.     

The Pleistocene subterranean volesTerricola (Rodentia) of Serbia and Montenegro

A general morphometrical analysis of the M₁ was conducted to identify the subterranean vole species found in Upper Pleistocene localities from Serbia and Montenegro, and to clarify the systematic position and the phylogenetic relationships between the different species in the Balkans. From the different localities studied, we can assign one population toMicrotus (Terricola) thomasi and the others to theM. (T.) subterraneus group. This study suggests thatM. (T.) grafi can be considered as a chronological sub-species ofM. (T.) subterraneus or as a different but phylogenetically very close species.     

Molecular-phylogenetic analysis of cyclopoids (Copepoda: Cyclopoida) from Lake Baikal and its water catchment basin

Baikalian cyclopoids represent one of the richest endemic faunas of freshwater cyclopoid copepods. The genus Diacyclops Kiefer, 1927 is the most numerous by species number in the lake. In this work, molecular-phylogenetic analysis of 14 species and 1 sub-species from Lake Baikal and its water catchment basin is performed. The regions of mitochondrial cytochrom-oxydase I (COI) and of nuclear small-subunit 18S rRNA were used as evolution markers. In the obtained set of COI gene sequences, an effect of synonymous substitution saturation is revealed. Baikalian representatives of the genus Diacyclops form at phylogenetic schemes by two markers a monophyletic group, it suggest their origin from a common ancestral form. Preliminary estimate of this group age is 20–25 My.     

Experimental hybridization between two sub-species of snails (Helix aspersa aspersa and Helix aspersa maxima): consequences for fertility,survival and growth

Summary

The experimental laboratory pairing of hermaphroditic snails of different sub-species, Helix aspersa aspersa (H.a.a) and H. aspersa maxima (H.a.m.), made it possible to obtain both reciprocal hybrids for the first time and to describe their growth. The relatively small number of matings observed (20–25%) was partly responsible for the small number of clutches obtained (10–13%). The cross H.a.a.M × H.a.m.F is more fertile than the reciprocal. The observed tendency to reproductive isolation (behavioural and anatomical) suggests that H.a.a. and H.a.m. should be considered as two sub-species. Hybridization is not accompanied by a beneficial heterosis effect since significant juvenile mortality and an increased variation in growth were observed. The small size of H.a.a. is a dominant characteristic, whereas the colour of the mantle edge in the Fl individuals is intermediate between the black of H.a.m. and the white of H.a.a. The Fl generation is fertile and gives F2 snails with an adult size close to that of H.a.a. but slower growing. This approach allows investigations into the mechanisms underlying the reproductive isolation of parental sub-species.     

Long-Term Spatiotemporal Dynamics and Factors Associated with Trends in Bare-Nosed Wombats

Geographically widespread species present challenges for conservation assessment. We used long-term spotlight surveys to assess spatiotemporal dynamics of bare-nosed wombats (Vombatus ursinus), encompassing 34 years of surveys for the Tasmanian mainland sub-species (V. u. tasmaniensis, 1985–2018) and 25 years for the Flinders Island sub-species (V. u. ursinus, 1994–2018). Wombat populations increased on the Tasmanian mainland by 2.59 times and on Flinders Island by 3.51 times ( = 1.05 and 1.1 times increase/yr, respectively). At smaller spatial scales on mainland Tasmania, increases in wombat counts generally occurred within meteorological regions and regional zones, except for the Central North (West Tamar) region where a decrease in wombats is linked to a sarcoptic mange disease epizootic. We used generalized additive models to assess relationships between variables and wombat counts. The most supported variables at the mainland Tasmania scale were (in order of importance) year, positive associations with time-lagged minimum temperature, Tasmanian devil (Sarcophilus harrisii) counts, and moonlight, and a negative association with time-lagged rainfall. Among meteorological regions, variables associated with wombat counts exhibited some heterogeneity, with temperature and rainfall the most frequently associated variables. Our long-term, large-scale, and ecologically diverse analysis of bare-nosed wombats supports spotlight monitoring as a valuable, relatively simple, and affordable survey method in Tasmania and beyond. © 2021 The Wildlife Society.     

The Rotifera of Malaysia and Singapore with remarks on some species

Summary An intensive and extensive sampling of all types of Malaysian and Singaporean freshwaters for zooplankton gave 165 species, sub-species and varieties of Rotifera, mainly belonging to the Monogononta. Bdelloida were rarely identified. The present records bring Malaysia and Singapore in line with other well studied tropical countries as far as Rotifera records are concerned. 7 new genera and over 50 species, subspecies, varieties and forms have been added to the Malaysian and Singaporean Rotifera records and interesting and marked morphological and size variation in species from previous records, have been noted.The richest (in species) fauna of Rotifera occurs in rice fields and ponds which have a seasonal succession of dry to wet conditions and vegetation which shelters the rotifers.The Malaysian and Singaporean Rotifera fauna is typically tropical with a dominance of the genus Brachionus over temperate genera like Keratella. Also very rare or missing are typical temperate genera like Ploesoma, Notholca and Synchaeta. The dominance of Brachionus in Malaysia is less evident than expected because only a very small proportion of samples were taken in limnetic situations where Brachionus clearly dominates in the tropics.     

Flavonoid variation of theAconitum jaluense complex (Ranunculaceae) in Korea

Thirteen flavonoid compounds were isolated and identified from five Korean species in theA. jaluense complex; they were glycosylated derivatives of the flavonols kaempferol, quercetin, and isorhamnetin, and of the flavone apigenin. The flavonoid data revealed the presence of two entities in the complex in Korea; one includesA. jaluense s. str. and the other includes the remaining four species which have identical flavonoid profiles. Based on these results, in conjunction with evidence from the morphology, it is suggested that the taxa should be recognized as two sub-species ofA. jaluense s. l. The flavonoid data also provide strong evidence for the occurrence of hybridization betweenA. jaluense s. str. andA. japonicum subsp.napiforme at Mt. Chiri in southern Korea.     

Molecular phylogenetic investigations of the Viviparidae (Gastropoda: Caenogastropoda) in the lakes of the Rift Valley area of Africa

The freshwater gastropod family Viviparidae is nearly cosmopolitan, but absent from South America. On the African continent, two genera are recognized; the widespread Bellamya and the monotypic Neothauma, which is confined to Lake Tanganyika. Most of the African Bellamya species are confined to the major lakes of the Rift Valley area in Africa, i.e. Lake Albert, Lake Malawi, Lake Mweru, and Lake Victoria. The phylogenetic analyses of mitochondrial (COI and 16S) and nuclear (H3, 18S and 28S) DNA inferred three major lake-clades; i.e. Lake Victoria/Kyoga/Albert, Lake Malawi and Lake Mweru/Bangweulu. The endemic B. rubicunda from Lake Albert and B. unicolor from Lake Kyoga were inferred to be part of the Lake Victoria clade. Bellamya capillata as identified by shell characters was polyphyletic in gene trees. The monophyletic Bellamya species radiation in Lake Malawi was most nearly related to the Lake Victoria/Kyoga/Albert-clade. Taxa from the Zambian lakes, Mweru and Bangweulu, were inferred together and placed ancestral to the other lakes. Neothauma tanganyicense was inferred as the sister-group to the Zambian Bellamya. Within the lake-clades the endemic radiations show very low genetic diversities (0–4.1% in COI), suggesting much faster morphological divergence than molecular divergence. Alternatively, Bellamya in Africa constitutes only a few species with several sub-species or eco-phenotypic morphs. The African viviparids were inferred to be the sister-group to a clade comprising Asian species, and the relatively low genetic diversity between the clades (12.6–15.5% in COI) makes a recent Miocene dispersal event from Asia to Africa much more likely than an ancient Gondwana vicarience distribution.     

Genetic diversity analysis in disjunct populations of Rhododendron arboreum from the temperate and tropical forests of Indian subcontinent corroborate Satpura hypothesis of species migration

Rhododendron arboreum of the family Ericaceae represents one of the ancient relict tree species of the genus showing extreme disjunction in the Indian subcontinent. It is represented by two sub-species viz., ssp. arboreum Smith in the forests of north-eastern India (temperate) and spp. nilagiricum (Zenker) Tagg distributed in the southern Western Ghats (tropical) of India with apparently no distribution in the intervening plains. 35 Samples corresponding to different locations in the tropical montane forests of Nilgiris and temperate forests of northeast India were analyzed for distribution of genetic variation using 25 random primers. Relatively high genetic diversity was measured in the temperate populations (Ht = 0.21; Nm = 1.13) than tropical Rhododendrons. The hierarchical analysis of molecular variance showed that among the total variance, 25% is residing within populations while 63% of variance is among regions apparently revealing that disjunct distribution has structured genetic differentiation pattern in this species. Grouping of samples was in conformity with their spatial distribution, which was confirmed by UPGMA cluster analysis and PCA scatter plot. The taxon with its unique distribution pattern and wide cross compatibility between sub-species is however threatened by low genetic variation and gene flow that catalyses it’s shifting towards genetic drift and hence long-term conservation strategies need to be formulated particularly for the tropical Rhododendron sub-species. Among the various hypotheses and theory proposed to explain the Malayan affinity in the flora and fauna of Western Ghats, Satpura hypothesis based on dispersal model of distribution largely explains the discontinues distribution of R. arboreum.     

Molecular characterisation and interpretation of genetic diversity within globally distributed germplasm collections of tall fescue (Festuca arundinacea Schreb.) and meadow fescue (F. pratensis Huds.)

Allohexaploid tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum [Schreb.] Darbysh.) is an agriculturally important grass cultivated for pasture and turf world-wide. Genetic improvement of tall fescue could benefit from the use of non-domesticated germplasm to diversify breeding populations through the incorporation of novel and superior allele content. However, such potential germplasm must first be characterised, as three major morphotypes (Continental, Mediterranean and rhizomatous) with varying degrees of hybrid interfertility are commonly described within this species. As hexaploid tall fescue is also a member of a polyploid species complex that contains tetraploid, octoploid and decaploid taxa, it is also possible that germplasm collections may have inadvertently sampled some of these sub-species. In this study, 1,040 accessions from the publicly available United States Department of Agriculture tall fescue and meadow fescue germplasm collections were investigated. Sequence of the chloroplast genome-located matK gene and the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) permitted attribution of accessions to the three previously known morphotypes and also revealed the presence of tall fescue sub-species of varying ploidy levels, as well as other closely related species. The majority of accessions were, however, identified as Continental hexaploid tall fescue. Analysis using 34 simple sequence repeat markers was able to further investigate the level of genetic diversity within each hexaploid tall fescue morphotype group. At least two genetically distinct sub-groups of Continental hexaploid tall fescue were identified which are probably associated with palaeogeographic range expansion of this morphotype. This work has comprehensively characterised a large and complex germplasm collection and has identified genetically diverse accessions which may potentially contribute valuable alleles at agronomic loci for tall fescue cultivar improvement programs.     

Plants recently discovered in Scotland

Summary

Saxifraga rosacea is recorded and Poa scotica described new to Scotland. The position of segregate taxa or breeding units within several species complexes is clarified within Scotland: (a) the hexaploid cytotype within the mostly tetraploid Campanula rotundifolia; (b) diploid Hedera helix and tetraploid H. hibernica;, (c) diploid and tetraploid Deschampsia cespitosa, D. alpina and D. parviflora; (d) octoploid sub-species scotica within usually hexaploid Festuca rubra; (e) an octoploid mountain Agrostis; (f) fertile hexaploid Potentilla anserina; (g) an approximately triploid aneuploid Vaccinium uliginosum ssp. microphyllum.