Modelling immunocontraception in disseminating systems

1997 ◽  
Vol 9 (1) ◽  
pp. 51 ◽  
Author(s):  
N. D. Barlow
Keyword(s):  
New Zealand ◽  
Population Density ◽  
Related Species ◽  
Breeding Population ◽  
Trichosurus Vulpecula ◽  
Wild Type ◽  
Target Species ◽  
Closely Related Species ◽  
Novel Technology ◽  
High Prevalence

Vectored immunocontraception is a novel technology and simple models are described to help predict whether, and how, it might work. That is, given that an effective immunocontraceptive agent can be produced, and given that it can be inserted into a microparasitic or macroparasitic infective vector, would the vector persist and reach a high prevalence in the host and, if so, would it sterilize a sufficient proportion of the host breeding population to significantly reduce its density? Both conditions are necessary for success. The first question is an epidemiological one, relating solely to disseminating systems and differing according to whether the vector itself is newly introduced or pre-existing. If it is newly introduced, the assumption is that it is present in some other geographical areas occupied by the same target species, or is found in closely-related species. If the vector already exists in the population, the issue is one of competition between the engineered and wild-type vectors. The second question is an ecological one, common to both non-disseminating and disseminating systems. Whatever level of sterilization the immunocontraception provides must translate into a significant reduction in population density, having regard to the nature and extent of compensatory, density-dependence mechanisms in the population. These two questions, together with other more minor issues, are addressed in turn with particular reference to models for immunocontraception of brushtail possums (Trichosurus vulpecula)in New Zealand.

scholarly journals Pipeline for the Rapid Development of Cytogenetic Markers Using Genomic Data of Related Species

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 113 ◽  
Author(s):  
Pavel Kroupin ◽  
Victoria Kuznetsova ◽  
Dmitry Romanov ◽  
Alina Kocheshkova ◽  
Gennady Karlov ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Genome Sequence ◽  
Related Species ◽  
Evolutionary Divergence ◽  
Whole Genome ◽  
Target Genome ◽  
Target Species ◽  
Closely Related Species ◽  
Chromosome Markers

Repetitive DNA including tandem repeats (TRs) is a significant part of most eukaryotic genomes. TRs include rapidly evolving satellite DNA (satDNA) that can be shared by closely related species, their abundance may be associated with evolutionary divergence, and they have been widely used for chromosome karyotyping using fluorescence in situ hybridization (FISH). The recent progress in the development of whole-genome sequencing and bioinformatics tools enables rapid and cost-effective searches for TRs including satDNA that can be converted into molecular cytogenetic markers. In the case of closely related taxa, the genome sequence of one species (donor) can be used as a base for the development of chromosome markers for related species or genomes (target). Here, we present a pipeline for rapid and high-throughput screening for new satDNA TRs in whole-genome sequencing of the donor genome and the development of chromosome markers based on them that can be applied in the target genome. One of the main peculiarities of the developed pipeline is that preliminary estimation of TR abundance using qPCR and ranking found TRs according to their copy number in the target genome; it facilitates the selection of the most prospective (most abundant) TRs that can be converted into cytogenetic markers. Another feature of our pipeline is the probe preparation for FISH using PCR with primers designed on the aligned TR unit sequences and the genomic DNA of a target species as a template that enables amplification of a whole pool of monomers inherent in the chromosomes of the target species. We demonstrate the efficiency of the developed pipeline by the example of FISH probes developed for A, B, and R subgenome chromosomes of hexaploid triticale (BBAARR) based on a bioinformatics analysis of the D genome of Aegilops tauschii (DD) whole-genome sequence. Our pipeline can be used to develop chromosome markers in closely related species for comparative cytogenetics in evolutionary and breeding studies.

scholarly journals The comparison of closely related groups of rodents by DNA/DNA annealing

1968 ◽  
Vol 12 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Anne McLaren ◽  
P. M. B. Walker
Keyword(s):  
New Zealand ◽  
Inbred Strain ◽  
Related Species ◽  
Closely Related Species ◽  
L Cell ◽  
Hydroxyapatite Column

Within the genus Apodemus, DNA from A. sylvaticus and A. flavicollis could be distinguished on the basis of reciprocal DNA/DNA annealing in agar, even when unfractionated DNA was used. In preliminary experiments, DNA from geographical races of A. sylvaticus could not be distinguished, nor could DNA from two closely related species of Peromyscus.Within the species Mus musvulus, the fast-renaturing fraction of L-cell DNA, separated on a hydroxyapatite column, was able to discriminate between L-cell (originating from the C3H inbred strain) and NZB (New Zealand Black) inbred strain DNA in agar.

Impact of bovine tuberculosis on a population of brushtail possums (Trichosurus vulpecula Kerr) in the Orongorongo Valley, New Zealand

2004 ◽  
Vol 31 (4) ◽  
pp. 389 ◽  
Author(s):  
A. Arthur ◽  
D. Ramsey ◽  
M. Efford
Keyword(s):  
Overall Survival ◽  
New Zealand ◽  
Population Density ◽  
Bovine Tuberculosis ◽  
Local Population ◽  
Trichosurus Vulpecula ◽  
Considerable Uncertainty ◽  
Highly Sensitive ◽  
Competing Models ◽  
The Impact

Brushtail possums are the main wildlife vectors of bovine tuberculosis (Tb) in New Zealand. Possum–Tb models form the basis of possum control aimed at eradicating the disease, and yet competing models show different behaviour, and are highly sensitive to parameters about which there is considerable uncertainty. One area of great uncertainty is the impact of the disease on possum populations. We investigated the impact of Tb on a local population of brushtail possums in the Orongorongo Valley, Wellington. Bovine Tb was first detected in 1997 at one site within an intensively studied population, but has not been detected in another intensively studied population 3 km away since the early 1980s. Using a Before-After-Control-Impact (BACI) analysis, detection of Tb coincided with a 42% (95% CI = 23–56%) reduction in the odds of apparent yearly survival of a possum >17 months of age, i.e. a decrease in yearly survival from 0.85 to 0.77 in 'good' years, and a decrease from 0.71 to 0.60 in 'bad' years. This suggests that Tb had a significant impact on overall survival. However, there was no impact on local population density in September each year due to compensatory recruitment.

New brittle-stars (Echinodermata: Ophiuroidea) from New Zealand waters

Zootaxa ◽  
2003 ◽  
Vol 352 (1) ◽  
pp. 1 ◽  
Author(s):  
DONALD G. MCKNIGHT
Keyword(s):  
New Species ◽  
New Zealand ◽  
Related Species ◽  
New Genus ◽  
Closely Related Species ◽  
Brittle Stars

Thirteen new species of brittle-stars (Ophiuroidea: Echinodermata) and one new genus are described from the New Zealand region. These include: Ophiacanthidae (Ophiolebes); Ophiomyxidae (Ophiolycus, Renetheo n. gen.); and Ophiuridae (Amphiophiura, Ophiocten, Ophiophycis, Ophiura (Dictenophiura), Ophiura (Ophiuroglypha), Ophiomidas, and Ophiophyllum). Keys are provided to the described species of Ophiophycis and 4 closely related species of Amphiophiura occurring around New Zealand.

scholarly journals ON THE ORIGIN OF THE CULTIVATED CHENOPODS (CHENOPODIUM)

Genetics ◽  
1974 ◽  
Vol 78 (1) ◽  
pp. 503-505
Author(s):  
Charles B Heiser ◽  
David C Nelson
Keyword(s):  
South America ◽  
Related Species ◽  
Chenopodium Quinoa ◽  
Type A ◽  
Wild Type ◽  
Closely Related Species ◽  
The Andes

ABSTRACT On the basis of morphology Chenopodium quinoa of the Andes and C. nuttalliae of Mexico appear to be very closely related species. Artificial hybrids have been secured between the two. It is suggested that both species may have been derived from the same original wild type. A weedy quinoa, C. quinoa var. melanospermum, is known from South America, but as yet a weed race closely related to C. nutalliae has not been reported from Mexico.

scholarly journals Revisiting suppression of interspecies hybrid male lethality in Caenorhabditis nematodes

2017 ◽  
Author(s):  
Lauren E. Ryan ◽  
Eric S. Haag
Keyword(s):  
Rna Interference ◽  
Sex Ratio ◽  
Related Species ◽  
Wild Type ◽  
Hybrid Male ◽  
Female Progeny ◽  
Closely Related Species ◽  
Interspecies Hybrids ◽  
Biased Sex Ratio ◽  
Interspecies Hybrid

AbstractWithin the nematode genus Caenorhabditis, C. briggsae and C. nigoni are among the most closely related species known. They differ in sexual mode, with C. nigoni retaining the ancestral XO male-XX female outcrossing system, while C. briggsae females recently evolved self-fertility and an XX-biased sex ratio. Wild-type C. briggsae and C. nigoni can produce fertile hybrid XX female progeny, but XO progeny are either 100% inviable (when C. briggsae is the mother) or viable but sterile (when C. nigoni is the mother). A recent study provided evidence suggesting that loss of the Cbr-him-8 meiotic regulator in C. briggsae hermaphrodites allowed them to produce viable and fertile hybrid XO male progeny when mated to C. nigoni. Because such males would be useful for a variety of genetic experiments, we sought to verify this result. Preliminary crosses with wild-type C. briggsae hermaphrodites occasionally produced fertile males, but they could not be confirmed to be interspecies hybrids. Using an RNA interference protocol that eliminates any possibility of self-progeny in Cbr-him-8 hermaphrodites, we find sterile males bearing the C. nigoni X chromosome, but no fertile males bearing the C. briggsae X, as in wild-type crosses. Our results suggest that the apparent rescue of XO hybrid viability and fertility is due to incomplete purging of self-sperm prior to mating.

Differential growth of bowel commensal Bacteroides species on plant xylans of differing structural complexity

2020 ◽  
Author(s):  
M Centanni ◽  
JC Hutchison ◽  
Susan Carnachan ◽  
Alison Daines ◽  
WJ Kelly ◽  
...  
Keyword(s):  
New Zealand ◽  
Related Species ◽  
Intervention Studies ◽  
Structural Complexity ◽  
Commensal Bacteria ◽  
Differential Growth ◽  
Closely Related Species ◽  
Bacteroides Species ◽  
Chemical Structures ◽  
Bacteroides Ovatus

© 2016 Elsevier Ltd Alterations to the composition of the bowel microbiota (dysbioses) are associated with particular diseases and conditions of humans. There is a need to discover new, indigestible polysaccharides which are selective growth substrates for commensal bowel bacteria. These substrates (prebiotics) could be added to food in intervention studies to correct bowel dysbiosis. A collection of commensal bacteria was screened for growth in culture using a highly-branched xylan produced by New Zealand flax. Two, Bacteroides ovatus ATCC 8483 and Bacteroides xylanisolvens DSM 18836 grew well on this substrate. The utilisation of the xylan was studied chromatographically and by constituent sugar analysis. The two closely related species utilised the xylan in different ways, and differently from their use of wheat arabinoxylan. The growth of Bacteroides species on other plant xylans having differing chemical structures was also investigated. Novel xylans expand the choice of potential prebiotics that could be used to correct bowel dysbioses.

Investigating brushtail possum (Trichosurus vulpecula) home-range size determinants in a New Zealand native forest

2017 ◽  
Vol 44 (4) ◽  
pp. 316 ◽  
Author(s):  
K. S. Richardson ◽  
C. Rouco ◽  
C. Jewell ◽  
N. P. French ◽  
B. M. Buddle ◽  
...  
Keyword(s):  
New Zealand ◽  
Population Density ◽  
Home Range ◽  
Disease Transmission ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Native Forest ◽  
Trichosurus Vulpecula ◽  
Age And Sex

Context The Australian brushtail possums (Trichosurus vulpecula) introduction to New Zealand has exacted a heavy toll on native biodiversity and presented the country with its greatest wildlife reservoir host for bovine tuberculosis (TB). Management efforts to control both possums and TB have been ongoing for decades, and the biology of possums has been studied extensively in Australia and New Zealand over the past 50 years; however, we still do not have a clear understanding of its home-range dynamics. Aims To investigate determinants of home range size by using a uniquely large dataset in the Orongorongo Valley, a highly monitored research area in New Zealand and compare our findings with those of other studies. Methods Possum density was estimated, for subpopulations on four 13-ha cage-trap grids, by the spatially explicit capture–mark–recapture analysis of trapping data from 10 consecutive months. Home ranges were estimated from trap locations using a 100% minimum convex polygon (MCP) method for 348 individuals and analysed with respect to grid, age and sex. Key results Mean (standard error) possum density, estimated as 4.87 (0.19), 6.92 (0.29), 4.08 (0.21) and 4.20 (0.19) ha–1 for the four grids, was significantly negatively correlated with mean MCP home-range size. Grid, age, and the interaction of age and sex were significantly related to home-range size. Older possums had larger home ranges than did younger possums. When ‘juvenile cohort’ and ‘adult cohort’ data were analysed separately, to investigate the significant interaction, males in the ‘adult cohort’ had significantly larger home ranges than did females, with the grid effect still being apparent, whereas neither sex nor grid effects were significant for the ‘juvenile cohort’. Conclusions Our findings indicate that, in addition to density, age and sex are likely to be consistent determinants of possum home-range size, but their influences may be masked in some studies by the complexity of wild-population dynamics. Implications Our findings have strong implications regarding both disease transmission among possums and possum management. The fact that adult males occupy larger home ranges and the understanding that possum home range increases as population density decreases are an indication that males may be the primary drivers of disease transmission in possum populations. The understanding that possum home range increases as population density decreases could be a direct reflection of the ability of TB to persist in the wild that counteracts current management procedures. If individuals, and particularly males, infected with TB can withstand control measures, their ensuing home-range expansion will result in possible bacteria spread in both the expanded area of habitation and new individuals becoming subjected to infection (both immigrant possums and other control survivors). Therefore, managers should consider potential approaches for luring possum males in control operations.

Differential growth of bowel commensal Bacteroides species on plant xylans of differing structural complexity

2020 ◽  
Author(s):  
M Centanni ◽  
JC Hutchison ◽  
Susan Carnachan ◽  
Alison Daines ◽  
WJ Kelly ◽  
...  
Keyword(s):  
New Zealand ◽  
Related Species ◽  
Intervention Studies ◽  
Structural Complexity ◽  
Commensal Bacteria ◽  
Differential Growth ◽  
Closely Related Species ◽  
Bacteroides Species ◽  
Chemical Structures ◽  
Bacteroides Ovatus

© 2016 Elsevier Ltd Alterations to the composition of the bowel microbiota (dysbioses) are associated with particular diseases and conditions of humans. There is a need to discover new, indigestible polysaccharides which are selective growth substrates for commensal bowel bacteria. These substrates (prebiotics) could be added to food in intervention studies to correct bowel dysbiosis. A collection of commensal bacteria was screened for growth in culture using a highly-branched xylan produced by New Zealand flax. Two, Bacteroides ovatus ATCC 8483 and Bacteroides xylanisolvens DSM 18836 grew well on this substrate. The utilisation of the xylan was studied chromatographically and by constituent sugar analysis. The two closely related species utilised the xylan in different ways, and differently from their use of wheat arabinoxylan. The growth of Bacteroides species on other plant xylans having differing chemical structures was also investigated. Novel xylans expand the choice of potential prebiotics that could be used to correct bowel dysbioses.

scholarly journals Contrasting Strategies of Provisioning and Chick Growth in two Sympatrically Breeding Albatrosses at Campbell Island, New Zealand

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 804-813 ◽  
Author(s):  
Susan M. Waugh ◽  
Henri Weimerskirch ◽  
Yyes Cherel ◽  
Peter A. Prince
Keyword(s):  
New Zealand ◽  
Related Species ◽  
Satellite Tracking ◽  
Tracking Data ◽  
Feeding Frequency ◽  
Chick Growth ◽  
Closely Related Species ◽  
Provisioning Rate ◽  
Provisioning Strategies ◽  
Campbell Island

Abstract The provisioning strategies of two closely related species of albatross breeding sympatrically were studied at Campbell Island, New Zealand. Black-browed Albatrosses (Diomedea melanophrys) had a higher provisioning rate of chicks than Grey-headed Albatrosses (D. chrysostoma) as a result of a higher feeding frequency. Provisioning and satellite-tracking data suggest that Black-browed Albatrosses forage over neritic waters in trips of up to 5 days, in combination with longer trips over oceanic waters. In contrast, it was not possible to separate clearly short and long trips in Grey-headed Albatrosses, but they probably forage mostly over oceanic waters, combined with rafting or feeding near the colony during stays of short duration at sea. No inter-annual differences in foraging trip duration were apparent between years for either species. Chicks were fed larger meals at older ages and when in poorer condition, probably due to a limitation on the rate of assimilation of food. For both species, chick condition after feeding did not influence the duration of foraging trips. Black-browed Albatrosses from Campbell Island feed locally in neritic waters and up to 2,000 km from the colony, in contrast to conspecifics from other sites which feed principally over neritic waters. Grey-headed Albatrosses were largely dependent on oceanic resources as for conspecifics studied elsewhere. This study shows that foraging and provisioning strategies are flexible within species, allowing them to exploit more or less distant resources.

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