Dispersal by Benthic Invertebrates: The in Situ Swimming Behaviour of the Amphipod Corophium Volutator

Studies of the dispersal behaviour of marine and estuarine benthic invertebrates have concentrated on the majority of species where the individuals disperse as a planktonic larva. The view that seems to be prevalent, summarised by Crisp (1974, 1976), is that larvae are an adaptation to allow species to colonise transient habitats and for species with adults of limited mobility to colonise distant habitats. The spreading of the species over wide areas has the advantages of reducing competition and facilitating greater genetic diversity, leaving the species more adaptable to subsequent environmental changes. These advantages are greater with longer distances travelled, and are an explanation for larvae spending up to several weeks drifting in the plankton, despite the acknowledged high mortality rates associated with the pelagic existence.

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Antibiotic-Resistant Bacteria in Green Turtle (Chelonia mydas) Rearing Seawater

Animals ◽

10.3390/ani11061841 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1841

Author(s):

Thanaporn Chuen-Im ◽

Korapan Sawetsuwannakun ◽

Pimmnapar Neesanant ◽

Nakarin Kitkumthorn

Keyword(s):

Antibiotic Resistance ◽

Bacterial Infection ◽

High Mortality ◽

Mortality Rates ◽

Sea Turtle ◽

Resistant Isolate ◽

Resistant Bacteria ◽

Antibiotic Resistant Bacteria ◽

Antibiotic Resistant ◽

Increased Risk

Antibiotic resistance of microorganisms is a serious health problem for both humans and animals. Infection of these bacteria may result in therapy failure, leading to high mortality rates. During an early intervention program process, the Sea Turtle Conservation Center of Thailand (STCCT) has faced high mortality rates due to bacterial infection. Previously, investigation of juvenile turtle carcasses found etiological agents in tissue lesions. Further determination of sea water in the turtle holding tanks revealed a prevalence of these causative agents in water samples, implying association of bacterial isolates in rearing water and infection in captive turtles. In this study, we examined the antibiotic resistance of bacteria in seawater from the turtle holding tank for a management plan of juvenile turtles with bacterial infection. The examination was carried out in three periods: 2015 to 2016, 2018, and 2019. The highest isolate numbers were resistant to beta-lactam, whilst low aminoglycoside resistance rates were observed. No gentamicin-resistant isolate was detected. Seventy-nine isolates (71.17%) were resistant to at least one antibiotic. Consideration of resistant bacterial and antibiotic numbers over three sampling periods indicated increased risk of antibiotic-resistant bacteria to sea turtle health. Essentially, this study emphasizes the importance of antibiotic-resistant bacterial assessment in rearing seawater for sea turtle husbandry.

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Life history, climate and biogeography interactively affect worldwide genetic diversity of plant and animal populations

Nature Communications ◽

10.1038/s41467-021-20958-2 ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

H. De Kort ◽

J. G. Prunier ◽

S. Ducatez ◽

O. Honnay ◽

M. Baguette ◽

...

Keyword(s):

Genetic Diversity ◽

Life History ◽

Evolutionary Dynamics ◽

Environmental Changes ◽

Peripheral Populations ◽

Plant Dispersal ◽

Weak Support ◽

Animal Populations ◽

Plant Groups ◽

Conservation Genetic

AbstractUnderstanding how biological and environmental factors interactively shape the global distribution of plant and animal genetic diversity is fundamental to biodiversity conservation. Genetic diversity measured in local populations (GDP) is correspondingly assumed representative for population fitness and eco-evolutionary dynamics. For 8356 populations across the globe, we report that plants systematically display much lower GDP than animals, and that life history traits shape GDP patterns both directly (animal longevity and size), and indirectly by mediating core-periphery patterns (animal fecundity and plant dispersal). Particularly in some plant groups, peripheral populations can sustain similar GDP as core populations, emphasizing their potential conservation value. We further find surprisingly weak support for general latitudinal GDP trends. Finally, contemporary rather than past climate contributes to the spatial distribution of GDP, suggesting that contemporary environmental changes affect global patterns of GDP. Our findings generate new perspectives for the conservation of genetic resources at worldwide and taxonomic-wide scales.

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Genetic diversity of the extremely rare Habenaria dentata and the rare Habenaria linearifolia (Orchidaceae) in South Korea: implications for population history and conservation

Plant Ecology and Evolution ◽

10.5091/plecevo.2018.1366 ◽

2018 ◽

Vol 151 (1) ◽

pp. 48-60

Author(s):

Mi Yoon Chung ◽

Hoa Thi Quynh Le ◽

Sungwon Son ◽

Huai Zhen Tian ◽

Myong Gi Chung

Keyword(s):

Genetic Diversity ◽

Southern China ◽

Geographic Location ◽

Population History ◽

Population Variation ◽

Conservation Strategies ◽

Ancestral Population ◽

Allozyme Diversity ◽

Glacial Origin

Background and aims – Since historical events often leave an indelible mark on levels of genetic diversity of plant populations, one may indirectly infer their evolutionary history with the help of current patterns of genetic diversity. The terrestrial orchid Habenaria dentata, an element of warm-temperate/subtropical vegetation, reaches its northernmost limits in the Korean Peninsula, and thus it is extremely rare there. As H. dentata was absent from the Peninsula during the Last Glacial Maximum (LGM), it is likely to be of post-glacial origin having arrived from either a single refugium or multiple refugia. However, its rare, temperate/boreal congener H. linearifolia might have persisted in situ in either macrorefugia or microrefugia on the Peninsula during the LGM.Methods – To test which hypothesis is most appropriate for each species, we investigated levels of allozyme-based (17 loci) genetic diversity and population genetic structure in the two only known populations of H. dentata and in 12 populations of H. linearifolia.Key results – No allozyme diversity was found in H. dentata (He = 0.000), whereas H. linearifolia exhibited low within-population variation (He = 0.060) and high among-population differentiation (FST = 0.237). We found little association between populations in relation to their geographic location; several populations presented individuals belonging to different clusters.Conclusions – Our results suggest that H. dentata likely originated from a single ancestral population (perhaps from southern Japan or southern China) through post-glacial dispersal, whereas H. linearifolia probably survived the LGM in situ in microrefugia situated at low to mid-elevated regions. We further suggest that separate conservation strategies for each species should be employed, given that the two taxa have different ecological and demographic traits and harbour different levels of genetic diversity.

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Optimizing Conservation Strategies for a Threatened Tree Species: In Situ Conservation of White Ash (Fraxinus americana L.) Genetic Diversity through Insecticide Treatment

Forests ◽

10.3390/f9040202 ◽

2018 ◽

Vol 9 (4) ◽

pp. 202 ◽

Cited By ~ 9

Author(s):

Charles Flower ◽

Jeremie Fant ◽

Sean Hoban ◽

Kathleen Knight ◽

Laura Steger ◽

...

Keyword(s):

Genetic Diversity ◽

Tree Species ◽

In Situ Conservation ◽

Conservation Strategies ◽

Fraxinus Americana ◽

Insecticide Treatment ◽

White Ash ◽

Threatened Tree Species

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Molecular Insights into the Fungus-Specific Serine/Threonine Protein Phosphatase Z1 in Candida albicans

mBio ◽

10.1128/mbio.00872-16 ◽

2016 ◽

Vol 7 (4) ◽

Cited By ~ 15

Author(s):

Emily Chen ◽

Meng S. Choy ◽

Katalin Petrényi ◽

Zoltán Kónya ◽

Ferenc Erdődi ◽

...

Keyword(s):

Candida Albicans ◽

High Mortality ◽

Protein Phosphatase ◽

Cyclic Peptide ◽

Fungal Infections ◽

The United States ◽

Mortality Rates ◽

Regulatory Proteins ◽

Structural Elements ◽

Novel Targets

ABSTRACT The opportunistic pathogen Candida is one of the most common causes of nosocomial bloodstream infections. Because candidemia is associated with high mortality rates and because the incidences of multidrug-resistant Candida are increasing, efforts to identify novel targets for the development of potent antifungals are warranted. Here, we describe the structure and function of the first member of a family of protein phosphatases that is specific to fungi, protein phosphatase Z1 (PPZ1) from Candida albicans . We show that PPZ1 not only is active but also is as susceptible to inhibition by the cyclic peptide inhibitor microcystin-LR as its most similar human homolog, protein phosphatase 1α (PP1α [GLC7 in the yeast Saccharomyces cerevisiae ]). Unexpectedly, we also discovered that, despite its 66% sequence identity to PP1α, the catalytic domain of PPZ1 contains novel structural elements that are not present in PP1α. We then used activity and pulldown assays to show that these structural differences block a large subset of PP1/GLC7 regulatory proteins from effectively binding PPZ1, demonstrating that PPZ1 does not compete with GLC7 for its regulatory proteins. Equally important, these unique structural elements provide new pockets suitable for the development of PPZ1-specific inhibitors. Together, these studies not only reveal why PPZ1 does not negatively impact GLC7 activity in vivo but also demonstrate that the family of fungus-specific phosphatases—especially PPZ1 from C. albicans —are highly suitable targets for the development of novel drugs that specifically target C. albicans without cross-reacting with human phosphatases. IMPORTANCE Candida albicans is a medically important human pathogen that is the most common cause of fungal infections in humans. In particular, approximately 46,000 cases of health care-associated candidiasis occur each year in the United States. Because these infections are associated with high mortality rates and because multiple species of Candida are becoming increasingly resistant to antifungals, there are increasing efforts to identify novel targets that are essential for C. albicans virulence. Here we use structural and biochemical approaches to elucidate how a member of a fungus-specific family of enzymes, serine/threonine phosphatase PPZ1, functions in C. albicans . We discovered multiple unique features of PPZ1 that explain why it does not cross-react with, and in turn compete for, PP1-specific regulators, a long-standing question in the field. Most importantly, however, these unique features identified PPZ1 as a potential target for the development of novel antifungal therapeutics that will provide new, safe, and potent treatments for candidiasis in humans.

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In situ Evidence on the Role of Benthic Invertebrates on the Decomposition of Drifting Algal Mats in a Brackish Water Ecosystem

2010 International Conference on Biosciences ◽

10.1109/biosciencesworld.2010.25 ◽

2010 ◽

Author(s):

Jonne Kotta ◽

Helen Orav-Kotta ◽

Tiina Paalme

Keyword(s):

Brackish Water ◽

Benthic Invertebrates ◽

Algal Mats ◽

Water Ecosystem

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Influence of Quaternary environmental changes on mole populations inferred from mitochondrial sequences and evolutionary rate estimation

Zoological Letters ◽

10.1186/s40851-021-00169-9 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Azusa Nakamoto ◽

Masashi Harada ◽

Reiko Mitsuhashi ◽

Kimiyuki Tsuchiya ◽

Alexey P. Kryukov ◽

...

Keyword(s):

Genetic Diversity ◽

Environmental Changes ◽

Late Quaternary ◽

Population Expansion ◽

Rapid Expansion ◽

Dependent Manner ◽

Distribution Analysis ◽

Land Bridge ◽

Mismatch Distribution Analysis ◽

Expansion Event

AbstractQuaternary environmental changes fundamentally influenced the genetic diversity of temperate-zone terrestrial animals, including those in the Japanese Archipelago. The genetic diversity of present-day populations is taxon- and region-specific, but its determinants are poorly understood. Here, we analyzed cytochrome b gene (Cytb) sequences (1140 bp) of mitochondrial DNA (mtDNA) to elucidate the factors determining the genetic variation in three species of large moles: Mogera imaizumii and Mogera wogura, which occur in central and southern mainland Japan (Honshu, Shikoku, and Kyushu), and Mogera robusta, which occurs on the nearby Asian continent. Network construction with the Cytb sequences revealed 10 star-shaped clusters with apparent geographic affinity. Mismatch distribution analysis showed that modes of pairwise nucleotide differences (τ values) were grouped into five classes in terms of the level, implying the occurrence of five stages for rapid expansion. It is conceivable that severe cold periods and subsequent warm periods during the late Quaternary were responsible for the population expansion events. The first and third oldest events included island-derived haplotypes, indicative of the involvement of land bridge formation between remote islands, hence suggesting an association of the ends of the penultimate (PGM, ca. 130,000 years ago) and last (LGM, ca. 15,000 years ago) glacial maxima, respectively. Since the third event was followed by the fourth, it is plausible that the termination of the Younger Dryas and subsequent abrupt warming ca. 11,500 years ago facilitated the fourth expansion event. The second event most likely corresponded to early marine isotope stage (MIS) 3 (ca. 53,000 years ago) when the glaciation and subsequent warming period were predicted to have influenced biodiversity. Utilization of the critical times of 130,000, 53,000, 15,000, and 11,500 years ago as calibration points yielded evolutionary rates of 0.03, 0.045, 0.10 and 0.10 substitutions/site/million years, respectively, showing a time-dependent manner whose pattern was similar to that seen in small rodents reported in our previous studies. The age of the fifth expansion event was calculated to be 5800 years ago with a rate of 0.10 substitutions/site/million years ago during the mid-Holocene, suggestive of the influence of humans or other unspecified reasons, such as the Jomon marine transgression.

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