scholarly journals Multiple separate cases of pseudogenized meiosis genes Msh4 and Msh5 in Eurotiomycete fungi: associations with Zip3 sequence evolution and homothallism, but not Pch2 losses

2019 ◽  
Author(s):  
Elizabeth Savelkoul ◽  
Cynthia Toll ◽  
Nathan Benassi ◽  
John M. Logsdon
Keyword(s):  
Life History ◽  
Aspergillus Nidulans ◽  
Pcr Primers ◽  
The Other ◽  
Sister Taxon ◽  
Sequence Evolution ◽  
Degenerate Pcr ◽  
Case System ◽  
Life History Variables ◽  
Meiosis Genes

AbstractThe overall process of meiosis is conserved in many species, including some lineages that have lost various ancestrally present meiosis genes. The extent to which individual meiosis gene losses are independent from or dependent on one another is largely unknown. Various Eurotiomycete fungi were investigated as a case system of recent meiosis gene losses after BLAST and synteny comparisons found Msh4, Msh5, Pch2, and Zip3 to be either pseudogenized or undetected in Aspergillus nidulans yet intact in congeners such as A. fumigatus. Flanking gene-targeted degenerate PCR primers applied to 9 additional Aspergillus species found (i) Msh4, Msh5, and Zip3 pseudogenized in A. rugulosus (sister taxon to A. nidulans) but intact in all other amplified sequences; and (ii) Pch2 not present at the syntenic locus in most of the 9 species. Topology tests suggested two independent Pch2 losses in genus Aspergillus, neither directly coinciding with pseudogenization of the other three genes. The A. nidulans-A. conjunctus clade Pch2 loss was not associated with significant Ka/Ks changes for Msh4, Msh5, or Zip3; this suggests against prior Pch2 loss directly altering sequence evolution constraints on these three genes. By contrast, Zip3 Ka/Ks tended to be elevated in several other Eurotiomycete fungi with independently pseudogenized Msh4 and Msh5 (Talaromyces stipitatus, Eurotium herbariorum). The coinciding Ka/Ks elevation and/or clear pseudogenization of Zip3 in taxa with pseudogenized Msh4 and Msh5 is consistent with some degree of molecular coevolution. Possible molecular, environmental, and life history variables (e.g., homothallism) that may be associated with these numerous independent meiosis gene losses (Msh4: 3, Msh5: 3, Zip3: ≥ 1, Pch2: 4) are discussed.

A field study of competition and interaction between Lemna minor and Lemna trisulca

1989 ◽  
Vol 67 (10) ◽  
pp. 2904-2911 ◽  
Author(s):  
Alexander L. McIlraith ◽  
Gordon G. C. Robinson ◽  
Jennifer M. Shay
Keyword(s):  
Life History ◽  
Field Study ◽  
Key Words ◽  
Field Experiments ◽  
Lemna Minor ◽  
Survey Methods ◽  
The Other ◽  
Transplant Experiment ◽  
Replacement Series ◽  
Vegetative Biomass

Field experiments and survey methods were used to assess competition and interaction between Lemna minor L. and Lemna trisulca L. at Delta Marsh, Manitoba. Sites were dominated by one or the other species or codominated by both. Replacement series experiments predicted codominance of L. minor and L. trisulca in an unshaded eutrophic site but predicted L. minor dominance when run for a longer time. Similar experiments conducted in a shaded eutrophic site predicted L. minor dominance. Addition series experiments showed that intraspecific and interspecific competition occurred in the unshaded site. In a eutrophic unshaded ditch, high densities of L. minor suppressed L. trisulca. In a eutrophic shaded site, high densities of L. minor and green algae inhibited L. trisulca, and in a sunny, less eutrophic site high density of each species inhibited the other. In a transplant experiment, L. minor biomass in shaded enclosures approached that found naturally in two shaded sites. Lemna trisulca persisted when shaded. Vegetative biomass trends in an unshaded eutrophic marsh ditch indicated spring and fall L. trisulca dominance and summer L. minor dominance. Shaded eutrophic sites were dominated by L. minor, whereas a less eutrophic site was dominated by L. trisulca. A model is developed to explain dominance patterns, and seasonal life-history responses are considered. Key words: Lemna, duckweed, competition, interaction, resources, light, nutrients.

scholarly journals On Apogamy and the development of Sporangia upon fern prothalli

1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61
Keyword(s):  
Life History ◽  
Point Of View ◽  
The Other ◽  
Normal Life ◽  
Other Hand ◽  
General Importance ◽  
Two Generations ◽  
History Of ◽  
Alternation Of Generations

The two most important deviations from the normal life-history of ferns, apogamy and apospory, are of interest in themselves, but acquire a more general importance from the possibility that their study may throw light on the nature of alternation of generations in archegoniate plants. They have been considered from this point of view Pringsheim, and by those who, following him, regard the two generations as homologous with one another in the sense that the sporophyte arose by the gradual modification of individuals originally resemblin the sexual plant. Celakovsky and Bower, on the other hand, maintaint the view tha t the sporophyte, as an interpolated stage in the life-history arising by elaboration of the zygote, a few thallophytes.

scholarly journals Effect of NaCl on seed germination in some Centaurium Hill. Species (Gentianaceae)

2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic
Keyword(s):  
Life History ◽  
Salt Tolerance ◽  
Seed Germination ◽  
Gibberellic Acid ◽  
White Light ◽  
The Other ◽  
Distilled Water ◽  
Nacl Concentration ◽  
History Of ◽  
Species Specific

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .

Identification of mariner-like elements in Sitodiplosis mosellana (Diptera: Cecidomyiidae)

2006 ◽  
Vol 138 (2) ◽  
pp. 138-146 ◽  
Author(s):  
O. Mittapalli ◽  
R.H. Shukle ◽  
I.L. Wise
Keyword(s):  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Blot Analysis ◽  
Copy Number ◽  
Southern Blot Analysis ◽  
Pcr Primers ◽  
Amino Acid Sequences ◽  
Degenerate Pcr ◽  
Sitodiplosis Mosellana ◽  
Wheat Midge

AbstractMariner-like element sequences were recovered from the genome of the orange wheat midge, Sitodiplosis mosellana (Géhin), with degenerate PCR primers designed to conserved regions of mariner transposases. The deduced amino acid sequences of the mariner-like transposases from S. mosellana showed 67% to 78% identity with the peptide sequences of other mariner transposases. A phylogenetic analysis revealed that the mariner-like elements from S. mosellana grouped in the mauritiana subfamily of mariner transposons. Results from Southern blot analysis suggest mariner-like elements are at a moderate copy number in the genome of S. mosellana.

scholarly journals Plasmodium infection decreases fecundity and increases survival of mosquitoes

2012 ◽  
Vol 279 (1744) ◽  
pp. 4033-4041 ◽  
Author(s):  
J. Vézilier ◽  
A. Nicot ◽  
S. Gandon ◽  
A. Rivero
Keyword(s):  
Life History ◽  
Insecticide Resistance ◽  
Life History Traits ◽  
Experimental System ◽  
Adaptive Strategy ◽  
Genetic Variations ◽  
The Other ◽  
Plasmodium Infection ◽  
Trade Off ◽  
The One

Long-lived mosquitoes maximize the chances of Plasmodium transmission. Yet, in spite of decades of research, the effect of Plasmodium parasites on mosquito longevity remains highly controversial. On the one hand, many studies report shorter lifespans in infected mosquitoes. On the other hand, parallel (but separate) studies show that Plasmodium reduces fecundity and imply that this is an adaptive strategy of the parasite aimed at redirecting resources towards longevity. No study till date has, however, investigated fecundity and longevity in the same individuals to see whether this prediction holds. In this study, we follow for both fecundity and longevity in Plasmodium- infected and uninfected mosquitoes using a novel, albeit natural, experimental system. We also explore whether the genetic variations that arise through the evolution of insecticide resistance modulate the effect of Plasmodium on these two life-history traits. We show that (i) a reduction in fecundity in Plasmodium- infected mosquitoes is accompanied by an increase in longevity; (ii) this increase in longevity arises through a trade-off between reproduction and survival; and (iii) in insecticide-resistant mosquitoes, the slope of this trade-off is steeper when the mosquito is infected by Plasmodium (cost of insecticide resistance).

Emergent Facilitation among Predators on Size-Structured Prey

2013 ◽  
Author(s):  
André M. de Roos ◽  
Lennart Persson
Keyword(s):  
Life History ◽  
Prey Species ◽  
The Other ◽  
Positive Interactions ◽  
Predator Species ◽  
Life History Stages ◽  
Specific Predator ◽  
Specialist Predators

This chapter discusses a variety of positive interactions between predators foraging on different stages of the same prey species, which all emerge owing to the biomass overcompensation that may occur in prey life history stages in response to increased mortality. These interactions include emergent facilitation of specialist predators by generalists that forage on the same prey individuals as the specialists, but in addition forage on smaller or larger prey individuals as well. Furthermore, the chapter shows that two predators that specialize on different life-history stages of prey can facilitate each other to the extent that one predator relies on the presence of the other for its persistence. A stage-specific predator may act as a catalyst species, which promotes and in fact is necessary for the invasion of another predator species, but is subsequently outcompeted by the latter.

The Odd Man Out in a Pioneer Cemetery at Seccombe Lake Park, San Bernardino, California

2020 ◽  
pp. 90-113
Author(s):  
Patricia M. Lambert
Keyword(s):  
Life History ◽  
Native American ◽  
Morphological Traits ◽  
The Other ◽  
European Ancestry ◽  
Latter Day Saints ◽  
Community Members ◽  
San Bernardino ◽  
History Of ◽  
The 19Th Century

In 1989, a pioneer cemetery associated with the 19th-century Latter-Day Saints colony in San Bernardino, California, was discovered during the construction of a baseball field. Among the remains of 12 individuals recovered from the cemetery were those of a young man of about 22 years, whose burial treatment differed notably from the other intact interments at the site. Unlike these coffin burials, Burial 5 was found in a sprawling position, apparently tossed unceremoniously into the grave pit. Dental morphological traits identified the genetic affinities of this man as Native American, perhaps a member of the local Cahuilla or Serrano tribes, whereas the other individuals appeared to be of European ancestry, an interpretation consistent with records kept by community members. A possible identity for this individual came from a journal account describing the shooting of an “Indian” by the local sheriff, who was then brought to the fort, died, and was buried before his fellow tribesmen arrived to determine what had transpired and perhaps to claim his remains. This chapter explores the identity and life history of this young man in the context of the history of the valley and the pioneer community in which he met his death.

The Biology of the Genus Pissodes. (George Heriot Research Fellowship Thesis.)

1902 ◽  
Vol 23 ◽  
pp. 319-358
Author(s):  
R. Stewart MacDougall
Keyword(s):  
Life History ◽  
Economic Importance ◽  
The Other ◽  
Remedial Measures ◽  
Research Fellowship ◽  
History Of ◽  
The One ◽  
Harmful Insect

In the case of any harmful insect of economic importance, in order to war against it, or apply remedial measures at all intelligently, a knowledge of the life-history of the pest is necessary. This proposition will, I think, meet with such ready acceptance as to render proof unnecessary, but I might in illustration mention two cases which came under my own observation, where in the one case a knowledge of the round of life of the attacking insect saved a whole forest, and in the other proved of great importance.

Sign in / Sign up

Export Citation Format

Share Document