scholarly journals Night diving by some emperor penguins during the winter breeding period at Cape Washington

2018 ◽  
Vol 221 (1) ◽  
pp. jeb170795 ◽  
Author(s):  
Gerald L. Kooyman ◽  
Robert P. van Dam ◽  
Luis A. Hückstädt
Keyword(s):  
Breeding Period ◽  
Emperor Penguins ◽  
Winter Breeding

scholarly journals Patterns of abundance and maturity among three species of parasitic nematodes (Pseudoterranova decipiens, Contracaecum osculatum, Anisakis simplex) co-existing in Sable Island grey seals (Halichoerus grypus)

2001 ◽  
Vol 3 ◽  
pp. 149 ◽  
Author(s):  
G Mark Fowler ◽  
Wayne T Stobo
Keyword(s):  
Prey Species ◽  
Final Host ◽  
Anisakis Simplex ◽  
Halichoerus Grypus ◽  
Parasitic Nematodes ◽  
Breeding Period ◽  
Cetacean Species ◽  
Pseudoterranova Decipiens ◽  
Contracaecum Osculatum ◽  
Winter Breeding

The abundance and maturity of three species of anisakine nematode (Pseudoterranova decipiens, Contracaecum osculatum, Anisakis simplex) that co-occurred in the stomachs of Sable Island grey seals were examined in relation to seal growth and seasonal considerations. Sealworm (P. decipiens), the predominant nematode in these seals, typically reached numbers of 400 to 2000 worms per stomach. C. osculatum and A. simplex were usually found in much smaller numbers of 40 to 100 and 20 to 60 worms, respectively, per stomach. All three species initially increased in abundance as the seals grew, but after most of a seals’ growth had been attained P. decipiens abundance continued to increase with age, A. simplex numbers either continued to increase or were simply maintained, while C. osculatum abundance declined. Numbers of both P. decipiens and A. simplex declined during winter breeding/pupping and summer moulting fasts or partial fasts, and rose during the regular feeding periods between the fasts. Conversely, numbers of C. osculatum rose during the breeding period, and also during the moulting period in younger seals. We believe this could be attributed to some degree of feeding on prey species in the immediate vicinity of Sable Island that were not preferred during focused feeding periods, and that the inclination to feed during fasting periods decreased as seals grew. An inverse relationship between worm abundance and worm maturity, attributable to the seasonal changes in rates of ingestion of immature worms, was more pronounced for C. osculatum than P. decipiens. C. osculatum was usually represented by much higher proportions of mature worms than P. decipiens. This could be entirely related to the longer periods of time dedicated to feeding than spent breeding or moulting, but higher mortality rates of immature C. osculatum or greater longevity of mature C. osculatum could also have occurred. A. simplex, generally associated with cetacean species as final hosts, rarely matured in grey seals. We have doubts that the grey seal could be considered a final host for A. simplex.

Blood parasitaemia in a high latitude flexible breeder, the white-winged crossbill,Loxia leucoptera: contribution of seasonal relapse versus new inoculations

Parasitology ◽  
2009 ◽  
Vol 137 (2) ◽  
pp. 261-273 ◽  
Author(s):  
P. DEVICHE ◽  
H. B. FOKIDIS ◽  
B. LERBOUR ◽  
E. GREINER
Keyword(s):  
Early Spring ◽  
Reproductive Hormones ◽  
Plasma Testosterone ◽  
Late Winter ◽  
Breeding Period ◽  
Adult Males ◽  
Vector Abundance ◽  
Respective Contribution ◽  
Free Ranging ◽  
Winter Breeding

SUMMARYWe measured seasonal changes in the prevalence of haematozoa (Leucocytozoon fringillinarum, Haemoproteus fringillae, andTrypanosoma avium) in free-ranging White-winged Crossbills,Loxia leucoptera, over 1·5 year in Fairbanks, Alaska, USA. This prevalence was low during early winter.L. fringillinarumprevalence increased in late winter/early spring, in the absence of vectors, suggesting relapse of latent infection. By contrast, the prevalence ofT. aviumandH. fringillaedid not increase until mid-spring, coincident with the emergence of putative vectors and suggestive of new inoculations. The winter breeding period was not associated with lower body condition or elevated blood heterophil/lymphocyte ratios than the summer post-breeding period. Thus, birds unlikely perceived their breeding effort as particularly stressful. Adult males in May and June had low plasma testosterone and their blood prevalence ofL. fringillinarum, but not other haemoparasites, was higher than in adult females. This difference may have resulted from sex differences in behaviour and/or plumage colouration – bright red in males, dull green/yellow in females. Species in which reproduction and vector abundance are seasonally dissociated may constitute important models for investigating the respective contribution of reproductive hormones, breeding effort, and vector abundance to patent and latent hemoparasitic infections and to new inoculations.

Winter Breeding in Emperor Penguins: A Consequence of the Summer Heat?

The Condor ◽  
1980 ◽  
Vol 82 (2) ◽  
pp. 159 ◽  
Author(s):  
Berry Pinshow ◽  
W. R. Welch
Keyword(s):  
Emperor Penguins ◽  
Summer Heat ◽  
Winter Breeding

The seasonality of reproduction in photoperiod responsive and nonresponsive northern red-backed voles (Myodes rutilus) in Alaska

2009 ◽  
Vol 87 (2) ◽  
pp. 152-164 ◽  
Author(s):  
K.T. Stevenson ◽  
I.G. van Tets ◽  
L.A.I. Nay
Keyword(s):  
Environmental Parameters ◽  
Late Summer ◽  
Reproductive Organ ◽  
Early Summer ◽  
Lower Latitude ◽  
Breeding Period ◽  
South Central ◽  
Myodes Rutilus ◽  
Field And Laboratory Conditions ◽  
Winter Breeding

High-latitude arvicoline rodents usually reproduce in warmer months, but winter breeding has been documented in several species, including the northern red-backed vole ( Myodes rutilus (Pallas, 1779) Wilson and Reader, 2005; formerly Clethrionomys rutilus (Pallas, 1779)). We tested whether the reproductive condition of the species is linked to changes in environmental parameters or its body condition, and we tested the frequencies at which different reproductive phenotypes are exhibited under field and laboratory conditions. Free-living voles in south-central Alaska reached peak reproductive organ masses in spring (females) and early summer (males). Between-subject comparisons showed an effect of body mass, photoperiod, percent fat, temperature, and snow depth on reproductive organ masses, depending on the sex and breeding period (p < 0.05). One instance of late-summer photoperiod nonresponsiveness was observed, but we detected no winter breeding. Captive male voles given food ad libitum and housed at room temperature exhibited strong phenotypic variation in testis mass in response to short photoperiods. The percentage of nonresponders was 28.2% and was within the known range of nonresponsiveness for lower latitude species (20%–40%). Thus, photoperiod nonresponsive morphs are conserved in at least one arctic and subarctic species at frequencies comparable to lower latitude voles despite no observance of winter breeding in the field. Voles exhibit reproductive elasticity and may breed in winter if environmental conditions enable them.

scholarly journals Mediterranean Pine Vole, Microtus duodecimcostatus: A Paradigm of an Opportunistic Breeder

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1639
Author(s):  
Miguel Lao-Pérez ◽  
Diaa Massoud ◽  
Francisca M. Real ◽  
Alicia Hurtado ◽  
Esperanza Ortega ◽  
...  
Keyword(s):  
Mammalian Species ◽  
Geographic Area ◽  
Breeding Period ◽  
Functional Regression ◽  
The Earth ◽  
Poplar Plantations ◽  
Microtus Duodecimcostatus ◽  
Mediterranean Pine ◽  
Animal House ◽  
Testis Regression

Most mammalian species of the temperate zones of the Earth reproduce seasonally, existing a non-breeding period in which the gonads of both sexes undergo functional regression. It is widely accepted that photoperiod is the principal environmental cue controlling these seasonal changes, although several exceptions have been described in other mammalian species in which breeding depends on cues such as food or water availability. We studied the circannual reproductive cycle in males of the Mediterranean pine vole, Microtus duodecimcostatus, in the Southeastern Iberian Peninsula. Morphological, hormonal, functional, molecular and transcriptomic analyses were performed. As reported for populations of other species from the same geographic area, male voles captured in wastelands underwent seasonal testis regression in summer whereas, surprisingly, those living either in close poplar plantations or in our animal house reproduced throughout the year, showing that it is the microenvironment of a particular vole subpopulation what determines its reproductive status and that these animals are pure opportunistic, photoperiod-independent breeders. In addition, we show that several molecular pathways, including MAPK, are deregulated and that the testicular “immune privilege” is lost in the inactive testes, providing novel mechanisms linking seasonal testosterone reduction and testis regression.

scholarly journals Genetic Diversity and Population Structure of Serbian Barley (Hordeum vulgare L.) Collection during a 40-Year Long Breeding Period

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Ljiljana Brbaklić ◽  
Dragana Trkulja ◽  
Sanja Mikić ◽  
Milan Mirosavljević ◽  
Vojislava Momčilović ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Hordeum Vulgare ◽  
Crop Improvement ◽  
Genetic Erosion ◽  
Breeding Period ◽  
Phenotypic Variance ◽  
Hordeum Vulgare L ◽  
Phenotypic Data ◽  
Breeding Material

Determination of genetic diversity and population structure of breeding material is an important prerequisite for discovering novel and valuable alleles aimed at crop improvement. This study’s main objective was to characterize genetic diversity and population structure of a collection representing a 40-year long historical period of barley (Hordeum vulgare L.) breeding, using microsatellites, pedigree, and phenotypic data. The set of 90 barley genotypes was phenotyped during three growing seasons and genotyped with 338 polymorphic alleles. The indicators of genetic diversity showed differentiation changes throughout the breeding periods. The population structure discriminated the breeding material into three distinctive groups. The principal coordinate analysis grouped the genotypes according to their growth habit and row type. An analysis of phenotypic variance (ANOVA) showed that almost all investigated traits varied significantly between row types, seasons, and breeding periods. A positive effect on yield progress during the 40-year long breeding period could be partly attributed to breeding for shorter plants, which reduced lodging and thus provided higher yield stability. The breeding material revealed a considerable diversity level based on microsatellite and phenotypic data without a tendency of genetic erosion throughout the breeding history and implied dynamic changes in genetic backgrounds, providing a great gene pool suitable for further barley improvement.

scholarly journals Female song in the Cyprus Wheatear Oenanthe cypriaca

2021 ◽  
Author(s):  
Robert Patchett ◽  
Alexander N. G. Kirschel ◽  
Joanna Robins King ◽  
Patrick Styles ◽  
Will Cresswell
Keyword(s):  
Breeding Season ◽  
Bird Species ◽  
Breeding Period ◽  
Territorial Defence ◽  
Multiple Functions ◽  
Male Song ◽  
Female Song ◽  
Mate Acquisition

AbstractFemale song is widespread across bird species yet rarely reported. Here, we report the first observations and description of female song in the Cyprus Wheatear Oenanthe cypriaca and compare it to male song through the breeding season. Twenty-five percent of colour-ringed females were observed singing at least once, predominantly in April, compared to 71% of males that continued singing through the breeding period. We suggest that female song may have multiple functions in this species, but it may be especially important in territorial defence and mate acquisition.

scholarly journals CRISPR/Cas9-mediated targeted mutagenesis in Japanese cedar (Cryptomeria japonica D. Don)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshihiko Nanasato ◽  
Masafumi Mikami ◽  
Norihiro Futamura ◽  
Masaki Endo ◽  
Mitsuru Nishiguchi ◽  
...  
Keyword(s):  
Genome Editing ◽  
Cryptomeria Japonica ◽  
Fluorescent Protein ◽  
Japanese Cedar ◽  
Targeted Mutagenesis ◽  
Embryogenic Tissue ◽  
Breeding Period ◽  
Single Mutation ◽  
Knock Out ◽  
Guide Rna

AbstractCryptomeria japonica (Japanese cedar or sugi) is one of the most important coniferous tree species in Japan and breeding programs for this species have been launched since 1950s. Genome editing technology can be used to shorten the breeding period. In this study, we performed targeted mutagenesis using the CRISPR/Cas9 system in C. japonica. First, the CRISPR/Cas9 system was tested using green fluorescent protein (GFP)-expressing transgenic embryogenic tissue lines. Knock-out efficiency of GFP ranged from 3.1 to 41.4% depending on U6 promoters and target sequences. The GFP knock-out region was mottled in many lines, indicating genome editing in individual cells. However, in 101 of 102 mutated individuals (> 99%) from 6 GFP knock-out lines, embryos had a single mutation pattern. Next, we knocked out the endogenous C. japonica magnesium chelatase subunit I (CjChlI) gene using two guide RNA targets. Green, pale green, and albino phenotypes were obtained in the gene-edited cell lines. Sequence analysis revealed random deletions, insertions, and replacements in the target region. Thus, targeted mutagenesis using the CRISPR/Cas9 system can be used to modify the C. japonica genome.

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