Cytogenetics of Mammalian Embryonic Development

Abstract

x+362pp. Oxford: Clarendon Press, 1987This monograph has an interesting history. It was first published in Russian by Nauka (Moscow) in 1978. The authors kindly sent copies to some fellow cytogeneticists in Britain who, after perusing it as well as they could, agreed that the Englishspeaking world should be given the chance of reading it too. Largely through the good offices of Dr Anne McLaren, Oxford University Press undertook to publish an English translation of an updated version and here it is. The translation has been accomplished very stylishly by one of the authors, V. S. Baranov, and OUP should be congratulated on their bold decision.The book deals in a systematic and thorough manner with an expanding field of enquiry. It is mainly devoted to experimental work on laboratory mammals, especially the mouse, but human examples of related phenomena (e.g. hydatidiform moles versus androgenetic embryos) are often described. The first seventy pages deal with effects of haploidy, triploidy etc. and how they arise. The authors then describe how numerical and structural changes come about, with emphasis on nondisjunctional mechanisms. Strangely, they do not include the fact that practically all existing reciprocal translocations in the mouse have been induced by radiation or radiomimetic chemicals whereas Robertsonian (whole arm) ones all seem to have arisen spontaneously in laboratory and wild populations. Next comes a detailed coverage of the various aneuploidy conditions in mice, on which they have worked extensively themselves. Inevitably, there is some overlap here and elsewhere with Epstein’s very useful monograph on the consequences of chromosome imbalance but they have different points of view, so the effect is additive rather than subtractive. The authors then describe in detail their studies on the developmental effects of chromosome imbalance generated by the well-known T6Ca translocation and some others, but comment that little work has been done in this field. This gap in our knowledge has been narrowed recently (see Progress and Topics in Cytogenetics, vol. 8) but much more needs to be done, especially on regions conserved between mouse and man.In a stimulating chapter on the functional activity of chromosomes and control mechanisms in early embryonic development, the authors discuss, inter alia, their own hypotheses on the initial regulation of development by ‘early genes’ (e.g. for actin and tubulin) clustered together on a few autosomes (Dyban) and on the importance of interchromosomal relationships and the mutual activation of homologous chromosomes in early embryogenesis (Baranov). This latter hypothesis would imply that, for the chromosomes concerned, monosomy and nulhsomy should have equally severe effects, since loci on a single unpaired chromosome would be more or less completely inactivated. We have recently disproved this for one mouse chromosome, since nullo-15’s die earlier than mono-15’s (Beechey & Searle, Cytogenet. Cell Genet.) but possibly the phenomenon, if it exists, is connected with chromosomes involved in genomic imprinting, which exonerates no. 15.The influence of specific genes on early mammalian development is also dealt with at some length and there is an interesting chapter on higher nervous activity in animals with chromosome anomalies. The latter is largely based on work by Soviet scientists. This brings out one very valuable aspect of this book, namely its inclusion of much relevant work by East European scientists which might be missed otherwise. In the Preface it is stated that Russian scientists “are always adequately informed on all scientific work published in English or in any other Western language.” Perhaps this is a slight exaggeration but it does point to a general informational imbalance, which this book helps to redress in one branch of biology at least The book is well illustrated and has about a thousand references, as well as a subject index. The authors’ goal for this new edition was to produce a book “of use to the English readers”; I feel sure that this will be.