EFTBA Veterinary Newsletter 30

EFTBA Veterinary Newsletter 30

EFTBA Veterinary Newsletter 30 April 2019 The Conventional . For centuries, breeders won- maternal dered whether the maternal versus grandsire effect grandsire may have an effect sympathetic on the offspring. - training . To answer such questions, wishful thinking geneticists investigated the or reality? parent-of-origin identification of genes in reciprocal hybrids (mules an hinnies). Races asine et chevaline de Poitou (Bonheur) . The results of this research allow to explain that some Welcome to EFTBA’s veterinary newsletter genes skip a generation. D ear Breeder, cation issues to name but a few. In many cases those in the position of This is normally a great time of year power are not fully understanding of for breeders as with each new foal our industry, when drafting and imple- born, we wonder if this is the one menting legislation, which can impin- “Many thanks to Mrs. which will put our name in lights; as ge our industry and livelihood negate- being a champion, or a big sale vely. These are some of the issues we Eva-Maria Bucher- horse (for those in the commercial should discuss at the upcoming EFTBA sector). We then worry if it will fulfil its Haefner, Moyglare 2019 AGM. genetic plan of being a successful, Stud Farm, for her correct and sound race horse. In the face of Brexit, I led a group of To this end, Hanspeter Meier will ex- concerned breeders, including mem- valued sponsorship bers of the EFTBA Executive and Paul plain how it works. Marie Gadot of France Galop to Brus- of this newsletter.” In the latest edition of the EFTBA sels on 22nd February 2019, during Veterinar y Newsletter Hanspeter laid which EU Lobbyist Michael Treacy had out in plain language how the ge- arranged a series of strategic mee- netic map will or should guide a tings with EU Commissioner Phil Hogan new born thoroughbred through its and senior EU officials who were part young life, how it develops to reach of the BREXIT negotiation team. It pro- its potential. There are many mile ved to be a beneficial delegation in stones, pitfalls, which may or may terms of highlighting the concerns of not be encountered that are be- European breeders and offering possi- yond the control of breeders or ble solutions in terms of free move- guardians, including safe birth, bio- ment of High Health Horses. Commis- security issues, scour, lameness as sioner Hogan, along with Dr. Alf-Eck- well as external factors such as poor bert Fussel, EU Commission’s Directo- husbandry and horsemanship, all of rate General on Animal Health as well which we hope to avoid with our as David Bruck, Donal O’Donnell, Tom stock. Tynan and Bernard Van Goethe have In the current climate of world ra- a good understanding of what is re- cing, our sport, our racing and as- quired and seemed willing to foster sociated way of life has never been and advance these requirements to under so much threat. The deve- facilitate continued movement and lopments at Santa Anita, welfare is- trade of bloodstock after the UK exits sues, taxational funding, or lack the- from the EU. 1 reof, changing of jockey rules, medi- Please be reassured your federation is working to stay on top of these and other issues challenging Genomic imprinting is an epigenetic phenome- our industry. If there are any questions you would non that causes genes to be expressed in a pa- like raised in advance of the AGM, please do not rent-of-origin-specific manner. Forms of genomic hesitate to contact me. I look forward to welcom- imprinting have been demonstrated in fungi, ing you to Kildare, Ireland on 24th May 2019. plants and animals. There are about 150 imprin- ted genes known in the mouse and about half Best regards that in humans. Genomic imprinting is an inheritance process in- Joe Hernon dependent of the classical Mendelian inheritan- Chairman, EFTBA ce. It is an epigenetic process without altering the genetic sequence. These epigenetic marks Editorial are established ("imprinted") in the germ-line (sperm or egg cells) of the parents and are main- In our last newsletter, we looked at results of genetic tained through mitotic cell divisions in the soma- studies in our time and possible connections with Oftic course, cells of these an organism scientists (Wikipedia). were above all interested traditional views on possible peculiarities of horse- breeding. There, our subjects were the mitochond- May these discoveries now help us breeders to ex- rial DNA and the dam-line in pedigrees. In this issue plain the “maternal grandsire effect” where traits now, we discuss the role of paternally expressed ge- may only be seen in later generations? – But first, let nes in the placenta of the mare. Is there an influen- us review some endeavors in investigating a pos- ce of the maternal grandsire on the offspring? Are sible role of the broodmare sire in the history of hor- the modern genetic findings in accordance with se breeding and the Thoroughbred. views of our ancestors on this subject? Let’s have a look at some publications on these questions in ear- The “maternal grandsire effect” in the lier times and scientific discoveries of today. history of breeding Dr Hanspeter Meier Presumptions of individual hereditary influences by EFTBA veterinary advisor & Newsletter editor the dam or the sire, most probably are as old as horse breeding itself. For instance, in the 18th cen- tury already, Prizelius (1777) expressed the opinion that the stallion contributes more to the procreation Introduction of a foal than the mare (“Die Erfahrung lehret es, Six years ago, Wang and co-workers from Cornell dass der Bescheler mehr zur Zeugung eines Füllens University (NY) published a very comprehensive beyträgt als eine Stute”). And - most interestingly - study with the title “Paternally expressed genes pre- he also added the remark that a foal exceptionally dominate in the placenta” and referred to earlier may present itself like an ancestor further back (“… studies with mouse embryos which had allowed the wobey jedoch, wiewohl selten, eine Ausnahme discovery that the paternal genome – by means of statt findet, indem ein Füllen auf das dritte Glied genomic imprinting – has a major influence on pla- zurück schlagen kann”). Although Prizelius just men- cental development. tioned personal experience(s), the history tells us that his remarks had a great influence on many Of course, these scientists were above all intere- breeders. sted to find out whether the phenomenon of geno- mic imprinting also exists in other mammals – and it Comparable notes e.g. are reported by Sir Charles certainly was a brilliant idea to select equids for the Leicester in his book ‘Bloodstock Breeding’; he had research in this field. With them, one is able to in- heard breeders of hunters in England and Ireland vestigate reciprocal hybrids of the horse and the aver that if they mated their broodmares to a Shire donkey - mules and hinnies. Here, genotypic differ- or other heavy horse in the first instance, the sub- rences allow the parent-of-origin identification of sequent foals by thoroughbred sires would be up to most expressed genes. more weight than if they had not followed this cour- se. According to Sir Charles, this attitude was so in- Using this approach, the scientists identified a core grained amongst farmer breeders of hunters in ear- group of 15 ancient imprinted genes, of which 10 lier times that a Thoroughbred sire as a first mate were paternally expressed (Wang et al., 2013). was rarely tried (Wright, 1983). 2 At the beginning of the 19th, such considerations ced a bay foal with a black dorsal line and a few were known under the conception “telegony”. dark (quagga like) stripes on its forehand and legs. To a subsequent mating to the same horse, she pro- Telegony was a theory in heredity, holding that duced another similarly marked foal. On discove- offspring can inherit the characteristics of a pre- ring this, Lord Morton sent details to the Royal Socie- vious mate of the female parent; thus the off- ty, whereupon many learned members of this insti- spring of a female might partake of traits of a tution accepted the facts as indisputable proof of previous sexual partner. the existence of telegony (Wright, 1983). Telegony was a very popular theory in the first However, other experts weren’t convinced of such th half of the 19 century among biologists, but a simple explanation and later, Sir Charles Leicester was largely dismissed with the arrival of Mende- mentioned photographs of two different pony foals lian genetics (1866). with similar but more abundant stripes. Neither of Experiments in the late 19th century on several the dams of these two pony foals had ever been species failed to provide evidence that off- near a quagga or zebra. The fact is that in some spring would inherit any character from their breeds of horses – and Sir Charles believes espe- mother's previous mates. However, in 2014 the cially amongst Norwegian ponies – these zebra evolutionary ecologists A.J. Crean and collea- stripes are sometimes seen. In his opinion, it was gues reported a similar phenomenon – passing pure coincidence that the peculiarity showed itself environmental (non-genetic) traits in a species in the two horses bred from Lord Morton’s mare of fly (Telostylinus angusticollis) (Wikipedia). (Wright, 1983). The most famous case of this alleged theory was Since those far-off days there have been innume- the following: In about 1815, Lord Morton mated a rable attempts to produce a similar result both by quagga stallion (a quagga is of the zebra species) crossing zebras etc., with mares and by other hybrid to a mare of seven/eights Arabian blood with the matings but all have failed.

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