Heritable and temperature-induced meristic variation in the medaka, Oryzias latipes

1974 ◽  
Vol 52 (8) ◽  
pp. 959-976 ◽  
Author(s):  
M. Y. Ali ◽  
C. C. Lindsey
Keyword(s):  
Developmental Stages ◽  
Phenotypic Variability ◽  
Response Patterns ◽  
Mechanical Shock ◽  
Heritable Variation ◽  
Paradoxical Reaction ◽  
Hatching Time ◽  
Rearing Conditions ◽  
Meristic Variation ◽  
Container Type

Eggs from 25 parental pairs were reared at sustained temperatures from 20C to 34C, or were changed from 20C to 30C or vice versa al various developmental stages. Crowding, mechanical shoes, container type, amount of aeration, and malachite green prophylaxis did not alter numbers of vertebrae, and pectoral or dorsal rays; nor did these numbers vary between eggs laid on different days by the same parents. Numbers of anal and caudal rays were significantly different between sibling egg batches, and were decreased by crowded rearing conditions. Mechanical shock increased anal ray counts. Caudal rays were sometimes decreased by lack of aeration. Response of vertebrae to different sustained temperatures was U-shaped in nine groups, with nadirs varying from 24C to 32C; in two groups, vertebrae were progressively fewer at higher temperatures. Pectoral ray counts usually were progressively lower at higher temperatures. Dorsal ray counts of most formed arched curves. In all series, heritable variation at one temperature roughly equalled phenotypic variability between temperatures. Inherited differences in response patterns of different meristic series are largely independent of each other, and of mortality and of hatching time. Temperature breaks produced an overcompensation in vertebrae if applied early, or a paradoxical reaction if applied late.

scholarly journals Validation of Functional Polymorphisms Affecting Maize Plant Height by Unoccupied Aerial Systems (UAS) allows Novel Temporal Phenotypes

2020 ◽  
Author(s):  
Alper Adak ◽  
Seth C. Murray ◽  
Clarissa Conrad ◽  
Yuanyuan Chen ◽  
Steven Anderson ◽  
...  
Keyword(s):  
Plant Height ◽  
Quantitative Trait ◽  
Genome Wide Association Study ◽  
Phenotypic Variability ◽  
Nucleotide Polymorphisms ◽  
Heritable Variation ◽  
Functional Polymorphisms ◽  
Tropical Germplasm ◽  
Hybrid Diversity ◽  
Aerial Systems

AbstractPlant height (PHT) in maize (Zea mays L.) has been scrutinized genetically and phenotypically due to relationship with other agronomically valuable traits (e.g. yield). Heritable variation of PHT is determined by many discovered quantitative trait loci (QTLs); however, phenotypic effects of such loci often lack validation across environments and genetic backgrounds, especially in the hybrid state grown by farmers rather than the inbred state preferred by geneticists. A previous genome wide association study using a hybrid diversity panel identified two novel quantitative trait variants (QTVs) controlling both PHT and grain yield. Here, heterogeneous inbred families demonstrated that these two loci, characterized by two single nucleotide polymorphisms (SNPs), cause phenotypic variation in inbred lines, but that size of these effects were variable across four different genetic backgrounds, ranging from 1 to 10 cm. Weekly unoccupied aerial system flights demonstrated both SNPs had larger effects, varying from 10 to 25 cm, in early growth while SNPs effects decreased towards the end of the season. These results show that allelic effect sizes of economically valuable loci are both dynamic in temporal growth and dynamic across genetic backgrounds resulting in informative phenotypic variability overlooked following traditional phenotyping methods. Public genotyping data shows recent favorably selection in elite temperate germplasm with little change across tropical backgrounds. As these loci remain rare in tropical germplasm, with effects most visible early in growth, they are useful for breeding and selection to expand the genetic basis of maize.

Flatworms (Schmidtea nova) prey upon embryos of the common frog (Rana temporaria) and induce minor developmental acceleration

2015 ◽  
Vol 36 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Ori Segev ◽  
Ariel Rodríguez ◽  
Susanne Hauswaldt ◽  
Karen Hugemann ◽  
Miguel Vences
Keyword(s):  
Developmental Plasticity ◽  
Developmental Stages ◽  
Rana Temporaria ◽  
Common Frog ◽  
Predator Species ◽  
Positive Effects ◽  
Hatching Time ◽  
Risk Of Predation ◽  
Frog Rana Temporaria ◽  
Indirect Cues

Amphibians vary in the degree of pre-metamorphic developmental plasticity in response to risk of predation. Changes in hatching time and development rate can increase egg or tadpole survival respectively by shortening the duration of the more vulnerable stages. The intensity of predator induced developmental response and its direction, i.e. delayed, accelerated, or none, varies considerably between amphibian and predator species. We surveyed freshly deposited clutches of the European common frog Rana temporaria in a population in Braunschweig, Germany and found that 62% (N = 20) of the clutches contained planarians (Schmidtea nova), with an average of 3.94 ± 0.79 and a maximum of 13 planarians per clutch. A laboratory predation experiment confirmed that this planaria preys on R. temporaria eggs and early embryos. We further exposed freshly laid egg masses to either free, caged, or no planarians treatments using floating containers within a breeding pond where the two species co-occur. After 10 days exposure, embryos showed developmental stages 14-25 along the Gosner scale with statistically significant positive effects of both predator treatments. The observed effect was rather slight as predator-exposed individuals showed an increase by a single Gosner stage relative to those raised without planarians. The detected trend suggests that direct and indirect cues from flatworms, rarely considered as anuran predators, might induce a developmental response in R. temporaria early developmental stages.

scholarly journals Long-term selection for a quantitative character in large replicate populations of Drosophila melanogaster: 1. Response to selection

1980 ◽  
Vol 35 (1) ◽  
pp. 1-17 ◽  
Author(s):  
B. H. Yoo
Keyword(s):  
Drosophila Melanogaster ◽  
Phenotypic Variability ◽  
Selection Response ◽  
Quantitative Character ◽  
Response Patterns ◽  
Total Response ◽  
Term Selection ◽  
Bristle Number ◽  
Selection For

SUMMARYThe response to long-term selection for increased abdominal bristle number was studied in six replicate lines of Drosophila melanogaster derived from the sc Canberra outbred strain. Each line was continued for 86–89 generations with 50 pairs of parents selected at an intensity of 20%, and subsequently for 32–35 generations without selection. Response continued for at least 75 generations and average total response was in excess of 36 additive genetic standard deviations of the base population (σA) or 51 times the response in the first generation. The pattern of longterm response was diverse and unpredictable typically with one or more accelerated responses in later generations. At termination of the selection, most of the replicate lines were extremely unstable with high phenotypic variability, and lost much of their genetic gains rapidly upon relaxation of selection.The variation in response among replicates rose in the early phase of selection to level off at approximately 7·6 around generation 25. As some lines plateaued, it increased further to a level higher than would be accommodated by most genetic models. The replicate variation was even higher after many generations of relaxed selection. The genetic diversity among replicates, as revealed in total response, the individuality of response patterns and variation of the sex-dimorphism ratio, suggests that abdominal bristle number is influenced potentially by a large number of genes, but a smaller subset of them was responsible for selection response in any one line.

A comparison of the susceptibility of the rice varieties, IR8 and Warangal 1263, to attack by the gall midge, Pachydiplosis oryzae (Wood-Mason)(Dipt., Cecidomyiidae)

1972 ◽  
Vol 61 (4) ◽  
pp. 745-753 ◽  
Author(s):  
W. W. D. Modder ◽  
A. Alagoda
Keyword(s):  
Body Length ◽  
Developmental Stages ◽  
Gall Midge ◽  
Mortality Rates ◽  
Rice Seedlings ◽  
Shoot Apices ◽  
Rice Varieties ◽  
Hatching Time ◽  
First Instar ◽  
Terminal Shoot

Daily observations were made of the developmental stages of Pachydiplosis oryzae (Wood-Mason) on laboratory-infested IR8 and W1263 rice seedlings at Peradeniya, Ceylon. The previously observed resistance of W1263 was attributed to the inhibition of moulting of first-instar larvae in 40% of the terminal shoot apices. In comparisons of the two varieties, differences in the following parameters were not significant or of no importance: the numbers of P. oryzae eggs laid and their hatching time, the mortality rates of the developmental stages, the number, body length and activity of the larvae and pupae at the terminal apices, and gall length.

scholarly journals Genome-wide association analysis for rice salt tolerance at seedling and reproductive stages

2021 ◽  
Author(s):  
Gang Chen ◽  
Keming Hu ◽  
Jianhua Zhao ◽  
Feifei Guo ◽  
Wenfeng Shan ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Genome Wide Association Study ◽  
Developmental Stages ◽  
Low Frequency ◽  
Genome Wide Association ◽  
Response Patterns ◽  
Nucleotide Polymorphisms ◽  
Rice Varieties ◽  
Genome Wide ◽  
Two Stages

Abstract Background Salinity is one of the main adverse environmental factors severely inhibiting rice growth and decreasing grain productivity. Developing rice varieties with salt tolerance (ST) is one of the most economical approaches to cope with salinity stress. However, the valuable resources for rice breeding towards ST remain to be identified. In this study, the salt tolerance of 220 rice accessions from RDP1, representing five subpopulations, were evaluated at both seedling and reproductive stages. Results An apparent inconsistency was found for ST between the two stages. Through a gene-based / tightly linked genome-wide association study, a total of 214 single nucleotide polymorphisms (SNPs) related to 251 genes, significantly associated with 16 ST-related indices, were detected at both stages. Eighty-two SNPs with low frequency favorable (LFF) alleles in the population were proposed to hold high breeding potential in improving rice ST. Fifty-four rice accessions collectively containing all these LFF alleles were identified as donors of these alleles. Through the integration of meta-QTL for ST and the response patterns of differential expression genes to salt stress, thirty-one candidate genes were suggested to be involved in the regulation of rice ST. Conclusions In total, the present study provides valuable information for further characterizing ST-related genes and for breeding ST varieties across whole developmental stages through marker-assisted selection (MAS).

scholarly journals Glassfrog embryos hatch early after parental desertion

2014 ◽  
Vol 281 (1785) ◽  
pp. 20133237 ◽  
Author(s):  
Jesse R. J. Delia ◽  
Aurelio Ramírez-Bautista ◽  
Kyle Summers
Keyword(s):  
Parental Care ◽  
Paternal Care ◽  
Developmental Stages ◽  
Wild Population ◽  
Developmental Rate ◽  
Embryo Survival ◽  
Hatching Time ◽  
Variation In Care ◽  
Removal Experiments ◽  
Hatching Process

Both parental care and hatching plasticity can improve embryo survival. Research has found that parents can alter hatching time owing to a direct effect of care on embryogenesis or via forms of care that cue the hatching process. Because parental care alters conditions critical for offspring development, hatching plasticity could allow embryos to exploit variation in parental behaviour. However, this interaction of parental care and hatching plasticity remains largely unexplored. We tested the hypothesis that embryos hatch early to cope with paternal abandonment in the glassfrog Hyalinobatrachium fleischmanni (Centrolenidae). We conducted male-removal experiments in a wild population, and examined embryos' response to conditions with and without fathers. Embryos hatched early when abandoned, but extended development in the egg stage when fathers continued care. Paternal care had no effect on developmental rate. Rather, hatching plasticity was due to embryos actively hatching at different developmental stages, probably in response to deteriorating conditions without fathers. Our experimental results are supported by a significant correlation between the natural timing of abandonment and hatching in an unmanipulated population. This study demonstrates that embryos can respond to conditions resulting from parental abandonment, and provides insights into how variation in care can affect selection on egg-stage adaptations.

Meristic variation in a clone of the cyprinodont fish Rivulus marmoratus related to temperature history of the parents and of the embryos

1986 ◽  
Vol 64 (7) ◽  
pp. 1444-1455 ◽  
Author(s):  
D. P. Swain ◽  
C. C. Lindsey
Keyword(s):  
Fresh Water ◽  
Developmental Stages ◽  
The Self ◽  
Temperature History ◽  
Vertebral Number ◽  
Rivulus Marmoratus ◽  
Temperature Regimes ◽  
Meristic Counts ◽  
History Of ◽  
Meristic Variation

Parents from one clone of the self-fertilizing cyprinodont fish Rivulus marmoratus were held at 25 or 30 °C, and their offspring were subjected to either a sustained temperature of 25 or 30 °C or to a temperature break (abrupt transfer in either direction between 25 and 30 °C) at various developmental stages. Effects of parental temperature before fertilization on meristic counts of offspring were determined both by comparing offspring produced either soon or long after parents had been transferred to a new temperature, and also by examining meristic responses of developing embryos to temperature breaks. Both line of evidence indicate that a parental temperature of 30 °C produces fewer vertebrae (0.31), pectoral rays (0.54), and caudal rays (1.11) than does one of 25 °C, in offspring reared under comparable temperature regimes. Neither line provides clear evidence of an effect of parental temperature on number of anal or dorsal rays in offspring. Responses of all five meristic series to temperature breaks in either direction were extralimitary (beyond the counts produced by sustained incubation at either temperature) and were satisfactorily fitted by an "atroposic" model described previously. Embryos transferred to fresh water during development tended to have higher meristic counts than those with sustained rearing in brackish water, but counts among embryos transferred to fresh water at different developmental stages differed significantly only for caudal rays. Only dorsal ray numbers differed significantly among embryos retained within parents for different times after fertilization. Previous studies claiming uniquely high thermolability of vertebral number in R. marmoratus are re-evaluated; thermolability of vertebral number in R. marmoratus is concluded to be within the range reported for other species.

Effect of Hypoxia on Embryo Development in Silkworm Eggs

2019 ◽  
Vol 113 (1) ◽  
pp. 55-61
Author(s):  
Jing Gong ◽  
Yuhao Zhang ◽  
Jiamin Yan ◽  
Shan Shang ◽  
Hanfei Gu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Embryonic Development ◽  
Developmental Stages ◽  
Classical Model ◽  
Early Embryogenesis ◽  
Embryo Morphology ◽  
Oxygen Species ◽  
Common Phenomenon ◽  
Hatching Time ◽  
Egg Diapause

Abstract Diapause is a common phenomenon during which organisms suspend development to overcome difficult environmental conditions. The silkworm is a classical model for the study of egg diapause. Our previous study showed that gene expression is similar in silkworm eggs treated with hyperoxia or HCl. In the present study, to further explore the mechanism of diapause prevention, nondiapause eggs and hyperoxia-/HCl-activated diapause eggs were treated with hypoxia. Embryo morphology, hatching time, and reactive oxygen species (ROS) levels were analyzed across different developmental stages. The results showed that hypoxia may inhibit the embryonic development of silkworm eggs. The morphology of nondiapause eggs under hypoxia differed from that of nondiapause eggs under normoxia during embryonic development, which, in turn, was similar to that of diapause eggs. Meanwhile, the hatching time of nondiapause eggs under hypoxia was delayed significantly. Moreover, the ROS levels of nondiapause eggs changed under hypoxia, showing a pattern similar to that of diapause eggs. Interestingly, when activated diapause eggs were treated with hypoxia, some eggs hatched in the following spring. These results suggest that early embryogenesis is largely dependent on oxygen levels and that hypoxia may induce a diapause-like state in activated diapause eggs. Additionally, ROS levels may play a key role in diapause. Thus, this study provides valuable information on the mechanisms of diapause and diapause prevention in silkworms.

scholarly journals Notes on the biological development of the darkling beetle Blaps nefrauensis nefrauensis Seidlitz, 1893 (Coleoptera: Tenebrionidae)

2022 ◽  
Vol 82 ◽  
Author(s):  
R. Amari ◽  
M. Gammoudi ◽  
H. Tlili ◽  
M. Ben Ali ◽  
A. Hedfi ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Late Summer ◽  
Nerve Fibers ◽  
Early Summer ◽  
Laboratory Rearing ◽  
Darkling Beetle ◽  
First Instar ◽  
Rearing Conditions ◽  
Biological Development ◽  
Coleoptera Tenebrionidae

Abstract Several endemic species of Blaps occur in Tunisia, and the species Blaps nefrauensis nefrauensis has been reported in Moulares (urban zone in west-central Tunisia), where it lives and reproduces in home gardens and old buildings. The aim of this work is to study the life cycle of the darkling beetle, considering both field and laboratory rearing conditions. As a result, the beetle species has different developmental stages (egg, larva, prepupa, pupa, and adult) that last about 15 months. Each year during the same period, adults emerge (early summer) and expire (late autumn), larvae hatch (late summer) and pupate (early summer). There is only one generation per year. Females began laying eggs in late July. The eggs were ovoid, white, and about 2.7 mm in length and 1.5 mm in width. Embryogenesis took an average of nine days. The first instar larvae were at initially only 4.5 mm long and ivory white in color. A brief description of the newly egg hatched larva was provided; thus, the nerve fibers innervating the apical setae in the antennae and ligula were detected. Further light microscopic examination of the embryo before hatching from the egg pointed out that the antennal sensilla are protected during the embryogenesis stage.

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