Biomedical subjects

C Marchaland

Publications and source records attributed to C Marchaland.

9 recordsLinked to original sources

PubMed1996

Vocalizations in newborn mice: genetic analysis.

Two kinds of vocalizations are produced by newborn mice: whistles (between 50 and 150 ms in length), having a narrow bandwidth in each strain that ranges from 30 to 90 kHz; and clicks, which are shorter (about 1 ms) and have a larger bandwidth. These vocalizations were individually recorded in 1-day-old pups from seven inbred strains of laboratory mice, at two temperatures (23 +/- 0.5 and 15 +/- 0.5 degrees C). The numbers of clicks and whistles were counted under these two conditions. Moreover, the length and frequencies at the beginning, apex, and end of the whistles were measured during the 15 degrees C condition. Correlations, including several components-additivity, epistasis (between homozygous loci), and maternal environment-were calculated between the characteristics of the whistles during the 15 degrees C condition. Clicks and whistles were also counted from 1 to 8 days of age during the 15 degrees C condition. The numbers of clicks and whistles were age dependent, with a decrease from day 1 to day 8 for the clicks and a consistent production of whistles. A quantitative genetic analysis was also performed on the 1-day-old pups from the Mendelian generations produced by the inbred strains most contrasting for the number of whistles produced in the cold condition: NZB/BINJ and CBA/H. The heterozygous genotype of the mother induced an increment of the number of whistles. Moreover, a significant part of the additive variance was suspected from the first design, and found with the second one, for this variable. Quantitative genetic analysis showed significant dominance and epistasis between homozygous loci and homozygous and heterozygous loci. This points to multigenic correlates for the number of whistles in this population. The significant additive values for all the variables recorded during the 15 +/- 0.5 degrees C condition and for the number of whistles produced during the 23 +/- 0.5 degrees C condition are compatible with an effect that indicates neither directional nor stabilizing selection. This result is examined in the light of the multichannel sensorial process implicated in maternal behavior in mice.

Animals↗

PubMed1996

Comparative diagnoses of twin zygosity by SSLP variant analysis, questionnaire, and dermatoglyphic analysis.

Zygosity diagnosis has been performed in 79 pairs of twins using three methods. Simple sequence repeat length polymorphism (SSLP) analysis allows an efficient classification (MZ or DZ) with only a few markers following a simplified technique of extraction and amplification. A method based on a full questionnaire completed by parents about twin similarity correctly classifies 97.46% of the pairs; 92.41% are correctly classified using only four questions as suggested by logistic regression analysis. The third method, using dermatoglyphic analyses, correctly classifies 86.76% of pairs. To lower the cost of DNA diagnosis we stress the possibility of limiting its use to pairs with scores in the overlap area between MZ and DZ twins with a validated questionnaire.

Child↗

PubMed1995

Long-term effects of embryo freezing in mice.

Embryo cryopreservation does not induce clear-cut anomalies at detectable rates, but several mechanisms exist for nonlethal damage during the freeze-thaw process, and the risk of moderate or delayed consequences has not been extensively investigated. In a long-term study including senescence, we compared cryopreserved and control mice for several quantitative traits. Significant differences were seen in morphophysiological and behavioral features, some of them appearing in elderly subjects. Thus, apart from its immediate toxicity, embryo cryopreservation, without being severely detrimental, may have delayed effects. These results, consistent with other findings, question the neutrality of artificial reproductive technologies and draw attention to the preimplantation stages in developmental toxicology.

Age Factors↗

PubMed1994

Evidence for a multigenic system controlling methyl-beta-carboline-3-carboxylate (beta-CCM)-induced seizures.

beta-CCM is a beta-carboline known to have properties opposite to those of benzodiazepines. Our approach was to analyze, in mice, the genetic mechanisms involved in beta-CCM-induced myoclonic seizures using recombinant congenic strains and F1 hybrids issued from these strains. Our aim was to define the extent of the multigenic character of beta-CCM-induced myoclonic seizures, while also evaluating the distribution of the strength of the genes implicated in this trait. The results show that the control of reactivity to beta-CCM is multigenic with notable epistatic involvement.

Animals↗

PubMed1994

Sibling resemblance in two manual laterality tasks.

Two tests of manual performance were adapted for French children: a dot-filling test and a tapping test. Sibling resemblance was assessed in a sample of 46 pairs of sibs. The power of intra-class correlation was estimated by a procedure of Approximate Randomization Tests. In both tests sibling resemblance was significant for overall level of motor skill (i.e. when the two hands were considered separately). Sibling resemblance was significant for degree of laterality in the dot-filling test (the closest task to writing) but not in the tapping test. The usefulness of including degree of laterality measures, in future genetic research is discussed.

Adolescent↗

PubMed1993

[Analysis of the behavior of rats in the Morris water-basin: new methodology and pharmacological application].

The Morris water-maze has been designed to test spatial orientation ability, learning and memory processes. In order to improve the analyse of the organization of the trajectory of rats, during the training phase, a computer program was elaborated. The study of the effect of a benzodiazepine, diazepam, was chosen to illustrate and validate this methodological approach. Results showed that rats pre-treated with diazepam (2 mg/kg) presented an impairment of spatial learning associated with the occurrence of a stereotyped circular swimming behaviour.

Animals↗

PubMed1992

Recombinant congenic strains of mice from B10.D2 and DBA/2: their contribution to behavior genetic research and application to audiogenic seizures.

Recombinant congenic strains (RCS) represent a series of related strains, each of which carries a small fraction of the genome of one strain ("donor" strain) on the genetic background of another strain ("background" strain). Recombinant inbred strains (RIS) are commonly used to identify major gene segregation and linkage and associations between behavior and quantitative trait loci, whereas recombinant congenic strains (RCS) open other complementary leads. The variability in the reactivity of RCS to a trait is thus the expression of few minor-effect genes originating from the donor strain, because the probability that major genes are present in any one RCS is low. Unlike RIS in which minor-effect genes are often masked by major genes, RCS enable the effects of minor genes to be studied. With our method, for a given trait, an estimate can be made of the gene strength distribution as well as an estimate of the minimal number of genes involved having a certain strength.

Acoustic Stimulation↗

PubMed1991

Handedness in mice: comparison across eleven inbred strains.

Screening for handedness was performed in 11 inbred strains of mice. Direction and degree of handedness were measured for both males and females in each strain. The data show that there are almost as many right- as left-handed subjects and no strain could be classified as right- or left-handed. Females, however, tend to be more strongly lateralized than males. The range of variation for degree of handedness is pronounced between strains. These results thus suggest that degree of handedness would be the relevant variable in a genetic analysis of handedness in mice. They are in agreement with Collins' previous results showing a response to selection for degree, but not for direction, of handedness.

Animals↗

PubMed1991

An assessment of handedness in mice.

Mice from a pool of inbred strains (384 males and 329 females) were tested for handedness according to Collins' protocol in order to assess the reliability of this measurement. As previously reported by Collins these data revealed that a) approximately half of the mice were right-handed and half left-handed, b) most of the mice were strongly lateralized and c) females were more lateralized than males. The study of the psychometric characteristics of the test suggested that this measurement of behavioral asymmetry is both stable and observer independent. The test of paw preference also appeared to measure preexisting lateralization and was not a function of training during the test.

Animals↗