The effects of using the wrong genetic model to predict the merit of crossbred genotypes

ABSTRACTThis paper evaluates the consequences of using the wrong genetic model when predicting the merit of previously untested crossbred genotypes. Eight models are considered, seven including different biological interpretations of two-locus epistatic interaction, plus one excluding epistatic effects. Published results from 13 genotypes generated from Hereford and Angus parental breeds were analysed, and predictions of a further seven genotypes made using different models. Under a dominance model, the predicted superiority in pregnancy rate (%) of a ¾ Hereford: ¼ Angus composite over a two-breed rotation was +1·2%, yet under all other models this was a negative value ranging from –1·9% to –3·7%. However, few such cases were found in which significant decision errors could conceivably be made. It is concluded that decisions on the choice of crossbred genotypes are generally quite robust to differences in the genetic model of the type studied here

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GENETIC ANALYSIS OF PLASMA CORTICOSTERONE LEVELS IN TWO INBRED STRAINS OF MICE

Journal of Endocrinology ◽

10.1677/joe.0.0550415 ◽

1972 ◽

Vol 55 (2) ◽

pp. 415-420 ◽

Cited By ~ 36

Author(s):

B. E. ELEFTHERIOU ◽

D. W. BAILEY

Keyword(s):

Genetic Analysis ◽

Recombinant Inbred ◽

Epistatic Interaction ◽

Genetic Model ◽

Inbred Strains ◽

Plasma Corticosterone ◽

Experimental Results ◽

Recombinant Inbred Strains ◽

Inbred Strains Of Mice

SUMMARY Plasma corticosterone levels were determined fluorometrically in mice of two unrelated highly inbred strains, C57BL/6By and BALB/cBy, and in seven of their derived recombinant-inbred strains as well as their F1 hybrid and backcross generations necessary to arrive at a genetic model for plasma corticosterone levels. It was concluded that the simplest genetic model, and one which fits the experimental results, was one which assumed that plasma corticosterone levels are controlled genetically by two loci with the epistatic interaction indicating dependency of pathways of action for the two genes.

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Bayesian Model Choice and Search Strategies for Mapping Interacting Quantitative Trait Loci

Genetics ◽

10.1093/genetics/165.2.867 ◽

2003 ◽

Vol 165 (2) ◽

pp. 867-883 ◽

Cited By ~ 19

Author(s):

Nengjun Yi ◽

Shizhong Xu ◽

David B Allison

Keyword(s):

Quantitative Trait Loci ◽

Quantitative Trait ◽

Complex Traits ◽

Bayesian Model ◽

Genetic Model ◽

Genetic Effects ◽

Monte Carlo Algorithm ◽

Data Set ◽

Epistatic Effects ◽

Trait Loci

AbstractMost complex traits of animals, plants, and humans are influenced by multiple genetic and environmental factors. Interactions among multiple genes play fundamental roles in the genetic control and evolution of complex traits. Statistical modeling of interaction effects in quantitative trait loci (QTL) analysis must accommodate a very large number of potential genetic effects, which presents a major challenge to determining the genetic model with respect to the number of QTL, their positions, and their genetic effects. In this study, we use the methodology of Bayesian model and variable selection to develop strategies for identifying multiple QTL with complex epistatic patterns in experimental designs with two segregating genotypes. Specifically, we develop a reversible jump Markov chain Monte Carlo algorithm to determine the number of QTL and to select main and epistatic effects. With the proposed method, we can jointly infer the genetic model of a complex trait and the associated genetic parameters, including the number, positions, and main and epistatic effects of the identified QTL. Our method can map a large number of QTL with any combination of main and epistatic effects. Utility and flexibility of the method are demonstrated using both simulated data and a real data set. Sensitivity of posterior inference to prior specifications of the number and genetic effects of QTL is investigated.

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In vitro-produced horse embryos exhibit a very narrow window of acceptable recipient mare uterine synchrony compared with in vivo-derived embryos

Reproduction Fertility and Development ◽

10.1071/rd19294 ◽

2019 ◽

Vol 31 (12) ◽

pp. 1904 ◽

Cited By ~ 3

Author(s):

Juan Cuervo-Arango ◽

Anthony N. Claes ◽

Tom A. E. Stout

Keyword(s):

Pregnancy Rate ◽

Pregnancy Loss ◽

Oestrous Cycle ◽

Ongoing Pregnancy ◽

Ongoing Pregnancy Rate ◽

Wide Range ◽

In Pregnancy

In recent years, the number of equine invitro-produced embryos (IVP) has increased markedly; as yet, there are few reports on what constitutes an ‘ideal’ recipient for an IVP embryo. This study retrospectively investigated the effects of recipient mare oestrous cycle characteristics on the likelihood of pregnancy after transfer of IVP (n=264) and invivo-derived embryos (n=262). IVP embryos tolerated only a narrow window of recipient mare ‘synchrony’, with transfer on Day 4 after ovulation resulting in a higher likelihood of ongoing pregnancy (69%) than transfer on Days 3, 5 or 6 (53.2%, 41.3% and 23.1% respectively; P=0.02). In contrast, Day 8 invivo-derived embryos tolerated a wide range of uterine (a)synchrony, with no difference in pregnancy or pregnancy loss for recipients that ovulated between Day 4 and Day 9 before transfer. However, transferring invivo-derived embryos to recipients that had a longer oestrus preceding transfer resulted in higher Day 12 and ongoing pregnancy rate (P<0.01). This effect was not significant in IVP embryos. In conclusion, Day 6–8 IVP blastocysts survive best after transfer to Day 4 recipient mares; Day 8 invivo-derived embryos survive equally well in Day 4–9 recipients, but do better in mares that have a long preceding oestrus.

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Decrease in pregnancy rate after endometrial scratch in women undergoing a first or secondin vitrofertilization. A multicenter randomized controlled trial

Human Reproduction ◽

10.1093/humrep/dey334 ◽

2018 ◽

Vol 34 (1) ◽

pp. 92-99 ◽

Cited By ~ 8

Author(s):

Sandrine Frantz ◽

Jean Parinaud ◽

Marion Kret ◽

Gaelle Rocher-Escriva ◽

Aline Papaxanthos-Roche ◽

...

Keyword(s):

Randomized Controlled Trial ◽

Pregnancy Rate ◽

Controlled Trial ◽

Randomized Controlled ◽

Multicenter Randomized Controlled Trial ◽

Endometrial Scratch ◽

In Pregnancy

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Clinical study of factors affecting outcome of tubal recanalization using microsurgical techniques: a retrospective study

International Journal of Reproduction Contraception Obstetrics and Gynecology ◽

10.18203/2320-1770.ijrcog20185181 ◽

2018 ◽

Vol 8 (1) ◽

pp. 35

Author(s):

Rashmi A. G. ◽

Shikha Singh

Keyword(s):

Family Planning ◽

Pregnancy Rate ◽

Child Loss ◽

Family Planning Services ◽

Factors Affecting ◽

Microsurgical Technique ◽

Child Desire ◽

Microsurgical Techniques ◽

Mini Laparotomy ◽

In Pregnancy

Background: In India, many couples complete their families by the age of 25 to 30 years and opt for tubal sterilization as a method of family planning in spite of availability of other spacing methods. Due to unforeseen circumstances, 10 % of them regret their decision and about 1% want to restore their fertility due to various reasons like loss of only child, loss of male child, desire to have more children, loss of children in natural calamities, remarriage and other socioeconomic factors. The objective of the present study was to analyze various factors which are involved in pregnancy rate in tubal recanalization.Methods: 31 women undergoing microsurgical tubal recanalization by mini laparotomy in RRMCH, Bengaluru during a study period of 2 year from 2014 -2016 were followed up for a period of 2 years by telephonic conversation.Results: An overall 67.7 % pregnancy rate was achieved with microsurgery technique.Conclusions: The important factors determining the success of operation were age of the patient, method of previous ligation and the remaining length of tube after recanalization. The microsurgical technique should be available at specialized centres to improve the success of family planning services and also this could be the hope for hopeless.

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Post-ovulation nutritional status in ewes does not influence early conceptus development in vivo or luteotrophic protein secretion in vitro.

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600023850 ◽

1993 ◽

Vol 1993 ◽

pp. 58-58

Author(s):

J.M. Wallace ◽

R.P. Aitken ◽

M.A. Cheyne

Keyword(s):

Pregnancy Rate ◽

Immunosuppressive Agents ◽

Maternal Environment ◽

Embryo Survival ◽

Domestic Species ◽

Progesterone Secretion ◽

Conceptus Development ◽

In Pregnancy

Overfeeding during early pregnancy compromises pregnancy establishment and /or embryo survival in a variety of domestic species including sheep, cattle and pigs (reviewed by Robinson, 1990). Embryo survival was reduced in recipient ewes receiving a high as opposed to a low plane of nutrition from embryo transfer on day 5 post-ovulation to day 60 of gestation (McKelvey & Robinson, 1988).Similarly high plane feeding for only 12 days starting on day 2 after mating significantly reduced pregnancy rates at day 60 ( Parr et al .,1987). Although not extensively monitored in either study, peripheral progesterone concentrations were inversely correlated with feed intake. Indeed, the reduction in pregnancy rate in high plane ewes in Parr's study was reversed by progesterone supplementation on days 8-14 after mating.The inhibition of luteolysis and maintenance of adequate progesterone secretion by the corpus luteum is central to the maternal recognition of pregnancy in sheep ( Bazer et al .,1991 ). Progesterone plays a major role in controlling maternal secretion of nutrients, growth factors , immunosuppressive agents .enzymes and steroids required for successful embryo development. It seems likely therefor that the mechanisms underlying nutritionally induced differences in pregnancy rate and embryo survival may operate via changes in progesterone levels which in turn alter the secretory dialogue between the conceptus and its maternal environment.

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RELATIONSHIP OF ELECTRICAL RESISTANCE OF VAGINAL MUCUS DURING OESTRUS WITH POST-AI PREGNANCY IN COWS

Bangladesh Journal of Veterinary Medicine ◽

10.3329/bjvm.v15i2.35520 ◽

2018 ◽

Vol 15 (2) ◽

pp. 113-117 ◽

Cited By ~ 2

Author(s):

M. Ahmed ◽

M. K. Chowdhury ◽

M. M. Rahman ◽

J. Bhattacharjee ◽

M. M. U. Bhuiyan

Keyword(s):

Pregnancy Rate ◽

Electrical Resistance ◽

Genital Tract ◽

Conception Rate ◽

Heat Detector ◽

The Mean ◽

The Difference ◽

Rectal Palpation ◽

Relationship Of ◽

In Pregnancy

Accurate detection of oestrus is a common problem for farmers to do AI timely resulting in conception failure in cows. The objective of the present study was to know the electrical resistance of vaginal mucus (ERVM) during oestrus to determine the best time of AI for improvement of conception in cattle. A total of 28 cows were inseminated with frozen thawed semen after detection of ERVM with Draminski estrus detector at Kendua Upazila Livestock Office under Netrakona district of Bangladesh. Pregnancy was diagnosed by per rectal palpation of genital tract 8-10 weeks after insemination. The mean ERVM in pregnant cows was 208.5 ± 31.2 Ω (163.3 to 263.3 Ω) and the ERVM in non-pregnant cows was 214.4 ± 36.6 Ω (153.3 to 280.0 Ω). Moreover, the pregnancy rate was higher in cows (80.0 to 83.3%) when ERVM during oestrus varied from 150 to 220 Ω than that of 221 to 280 Ω counterpart (36.4%). The difference in pregnancy rates between groups was significant (P<0.05). The present study indicates that Dramniski electrical heat detector may be used for prediction of time for AI in cows of Bangladesh. Up to 220 Ω ERVM during oestrus is better for higher conception rate than that of more than 220 Ω counterparts. Further studies with high number of inseminated cows should be conducted before wide application of this electrical heat detector under field conditions in Bangladesh.

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Acupuncture Prior to and at Embryo Transfer in An Assisted Conception Unit – a Case Series

Acupuncture in Medicine ◽

10.1136/aim.24.1.23 ◽

2006 ◽

Vol 24 (1) ◽

pp. 23-28 ◽

Cited By ~ 5

Author(s):

David Johnson

Keyword(s):

Success Rate ◽

Pregnancy Rate ◽

Embryo Transfer ◽

Assisted Reproduction ◽

Case Series ◽

In Vitro Fertilisation ◽

Assisted Conception ◽

Before And After ◽

In Pregnancy

Over a period of three years, acupuncture was offered to patients entering assisted reproduction therapy. Acupuncture sessions were given at varying, but usually weekly, intervals during the in vitro fertilisation (IVF) cycle, and immediately before and after embryo transfer. Twenty two patients (average age 36.2 years) were treated over a total of 26 IVF cycles and 15 pregnancies were achieved, as determined by presence of foetal heartbeat on ultrasound at four weeks post embryo transfer. This was a success rate of 57.7% compared with 45.3% for patients in the IVF unit not treated with acupuncture (P>0.05). Relaxing effects were noted following acupuncture and it is speculated that this may have contributed to the increase in pregnancy rate for the acupuncture group.

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