Prevalence of Antibodies to Neospora caninum and Toxoplasma gondii in Swedish Dogs

Neospora caninum is a newly described coccidian parasite which has been found in various species such as the dog, cattle, horse, sheep and goat. Morphologically it resembles Toxoplasma gondii with which it is related (Holmdahl et al. 1994), and with which it has earlier been confused. The life cycle of N caninum is only partially known. Tachyzoites and tissue cysts are the only known stages of the parasite, and transplacental transmission is the only known route of infection. Subclini-cally infected dams can transmit the parasite to their fetuses and successive offspring from the same mother might be born infected (Dubey et al. 1990b). Clinical neosporosis is mostly seen in pups or young dogs, and the majority or all pups in a litter are often affected. The disease is characterized by ascending paralysis of the legs, with the hind legs more severely affected than the front legs, paralysis of the jaw, difficulty in swallowing and muscle flaccidity and atrophy (Dubey 1992, Dubey & Lindsay 1993). Fatal infections with N caninum in dogs have been reported from many countries, e.g. Norway (Bjerkäs & Presthus 1988), USA (Dubey et al. 1988), Sweden (Uggla et al. 1989a,b) and the United Kingdom (Dubey et al. 1990a). Serological surveys for antibodies to N. caninum in dogs from Kansas, USA and England have shown a prevalence of 2 and 13%, respectively (Lindsay et al. 1990, Trees et al. 1993).     

中国转刺蛛属的修订(蜘蛛目:园蛛科)

对中国转刺蛛属Eriophora进行了修订,共记述8种,其中含3个新组合：宝天曼转刺蛛Eriophora baotianmanensis（Hu,Wang＆Wang,1991）和喜马拉稚转刺蛛Ehimalayaensis（Tikader,1975）从园蛛属Araneus移人,杂斑转刺蛛E．poecila（Zhu＆Wang,1994）从扇蛛属历肛n移人;3个新异名：王氏转刺蛛E.wangi Zhu et Song,1994和陕西转刺蛛E.shaanxiensis Zhu et Wang,1994均为宝天曼转刺蛛Ebaotianmanensis（Hu．Wang＆Wang,1991）的异名,松林园蛛A．pineus Yin et a1．,1990为萨哈林转刺蛛E.sachalinensis（Saito．1934）的异名。     

CFTR: Domains, Structure, and Function

Mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis (CF) (Collins, 1992). Over 500 naturally occurring mutations have been identified in CF gene which are located in all of the domains of the protein (Kerem et al., 1990; Mercier et al., 1993; Ghanem et al., 1994; Fanen et al., 1992; Ferec et al., 1992; Cutting et al., 1990). Early studies by several investigators characterized CFTR as a chloride channel (Anderson et al.; 1991b,c; Bear et al., 1991). The complex secondary structure of the protein suggested that CFTR might possess other functions in addition to being a chloride channel. Studies have established that the CFTR functions not only as a chloride channel but is indeed a regulator of sodium channels (Stutts et al., 1995), outwardly rectifying chloride channels (ORCC) (Gray et al., 1989; Garber et al., 1992; Egan et al., 1992; Hwang et al., 1989; Schwiebert et al., 1995) and also the transport of ATP (Schwiebert et al., 1995; Reisin et al., 1994). This mini-review deals with the studies which elucidate the functions of the various domains of CFTR, namely the transmembrane domains, TMD1 and TMD2, the two cytoplasmic nucleotide binding domains, NBD1 and NBD2, and the regulatory, R, domain.     

New Phytologist 140 (1998), 363–383

In the November 1998 issue of New Phytologist , we published the Tansley review 'Gibberellins: regulating genes and germination' by Sian Ritchie and Simon Gilroy ( New Phytol. (1998) 140 , 363–383). Since its publication, it has come to our attention that text associated with Fig. 4 was omitted during production. The correct figure is reprinted here in full.
We apologise to the author and to our readers for this mistake.
Figure 4. Promoter sequences of various genes expressed in the cereal aleurone and shown to be regulated by GA. The position of each sequence is indicated relative to the start codon. Regions identified as being involved in regulation of the genes are highlighted, as are similar regions in other genes. Sites at which protein has been shown to bind are also indicated. ( a ) Barley Amy 32b (Sutcliff et al ., 1993; Whittier et al ., 1987); wheat Amy 2/54 (Huttley et al ., 1992; Rushton et al ., 1992; Rushton et al ., 1995); barley Amy 46 (Khursheed & Rogers, 1988); barley Amy 2/p155 (Knox et al ., 1987); barley aleurain (Whittier et al ., 1987); barley β-glucanase II (Wolf, 1992); wheat cathepsin B-like (Cejudo et al ., 1992); rice ubiquitin-conjugating enzyme (Chen et al ., 1995). ( b ). Wheat Amy 1/18 (Rushton et al ., 1992); barley Amy pHV 19 (Jacobsen & Close, 1991; Gubler & Jacobsen, 1992)/ Amy 1 / 6-4 (Khursheed & Rogers, 1988; Rogers, Lanahan & Rogers 1994); rice OSamy-a / Amy 3c (Ou-Lee et al ., 1988; Sutcliff et al ., 1991; Yu et al ., 1992; Goldman et al ., 1994); rice Amy 3B (Sutcliffe et al ., 1991); rice OSamy-c (Kim et al ., 1992; Kim & Wu, 1992; Tanida et al ., 1994); rice Amy 1A (Huang et al ., 1990; Itoh et al ., 1995).
Figure 4 ( b ). For legend see facing page.     

Neospora caninum Infection in a Litter of Labrador Retriever Dogs in Denmark

Neospora caninum is a recently recognized cyst-forming coccidian parasite associated with severe encephalomyelitis and myositis in dogs of different breeds and ages (Bjerkås et al 1984, Bjerkås & Presthus 1988, Dubey et al. 1988), but has for many years been misdiagnosed as Toxoplasma gondii. In some dogs, the main clinical sign has been attributed to polyradiculoneuritis (Dubey et al. 1988, Cuddon et al. 1992). Furthermore, ulcerative dermatitis (Dubey et al. 1988) and megaoesophagus have been reported (Wolf et al. 1991). The life cycle of the parasite and mode of infection have not been clarified, but transplacental infection seems so far to be the natural route of transmission between intermediate hosts (Dubey & Lindsay 1989). It has been speculated that the disease in young and adult dogs might be due to reactivation of a persistent infection because corticosteroid therapy can activate a latent N. caninum infection (Dubey & Lindsay 1993).     

Multiple Forms and Distribution of Calcium/Calmodulin-Stimulated Protein Kinase II in Brain

In recent years, the enzyme Ca²⁺/calmodulin-stimulated protein kinase II¹ (CaM-PK II) as attracted a great deal of interest. CaM-PK II is the most abundant calmodulin-stimulated protein kinase in brain, where it is particularly enriched in neurons (Ouimet et al., 1984; Erondu and Kennedy, 1985; Lin et al., 1987; Scholz et al., 1988). Neuronal CaM-PK II has been suggested to be involved in several phenomena associated with synaptic plasticity (Lisman and Goldring, 1988; Kelly, 1992), including long-term potentiation (Malinow et al., 1988; Malenka et al.,1989), neurotransmission (Nichols et al., 1990; Siekevitz, 1991), and learning (for review, see Rostas, 1991). This enzyme has also been postulated to be selectively vulnerable in several pathological condition, including epilepsy/kindling (Bronstein et al.,1990; Wu et al., 1990), cerebral ischemia (Taft et al., 1988), and organophosphorus toxicity (Abou-Donia and Lapadula, 1990).     

A Case of Neospora Associated Bovine Abortion in Sweden

Neospora caninum is a recently recognized protozoan organism that causes fatal neuromuscular disease in dogs and abortions and stillbirths in cattle and other animals (Dubey & Lindsay 1993). The parasite is morphologically similar and phylogenetically very closely related to the cyst-forming coccidium Toxoplasma gondii (Ellis et al. 1994, Holmdahl et al. 1994). This group of parasites has a two-host life cycle principally involving a carnivorous definitive host and a herbivorous or omnivorous intermediate host. However, with N. caninum, there is as yet no knowledge of any definitive host harbouring sexual stages of the parasite. The only known route of transmission is vertical from mother to foetus (Dubey & Lindsay 1993).     

Diagnosis and seroepidemiology of Neospora caninum-associated bovine abortion

A round table was conducted at the VIIIth International Coccidiosis Conference on Neospora diagnosis with particular emphasis on strategies to diagnose bovine abortion. The strength and weakness of different assays for Neospora caninum infection and whether these methods have resulted in the overdiagnosis of neosporosis was discussed. It was evident that each diagnostic method, namely histology, immunohistochemistry, molecular detection and serological assays were, under certain circumstances, valuable in assessing the role N. caninum in abortion. Histological, immunohistochemical and molecular detection assays are of outstanding importance for the examination of tissues of aborted foetuses. While histology and immunohistochemistry allow direct assessment of pathomorphological changes caused by infection, molecular detection assays such as PCR are superior because of higher sensitivity and specificity in identifying N. caninum in foetal tissues. Serological tests, such as ELISA, are useful in determining whether an animal has been infected with N. caninum. Seroepidemiological approaches allow one to assess an abortion problem at a herd level and when used in conjunction with certain statistical methods are able to confirm a suspected N. caninum-associated abortion.     

Flow cytometric analysis of European flat oyster, Ostrea edulis, haemocytes using a monoclonal antibody specific for granulocytes

The importance of haemocytes in mollusc defence mechanisms can be inferred from their functions. They participate in pathogen elimination by phagocytosis (Cheng, 1981; Fisher, 1986). Hydrolytic enzymes and cytotoxic molecules produced by haemocytes contribute to the destruction of pathogenic organisms (Cheng, 1983; Leippe & Renwrantz, 1988; Charlet et al., 1996; Hubert et al., 1996; Roch et al., 1996). Haemocytes may also be involved in immunity modulation by the production of cytokines and neuropeptides (Hughes et al., 1990; Stefano et al., 1991; Ottaviani et al., 1996). As a result, the literature dealing with bivalve haemocyte studies has increased during the last two decades. Most of these publications use microscopy for morphological analysis (Seiler & Morse, 1988; Auffret, 1989; Hine & Wesney, 1994; Giamberini et al., 1996; Carballal et al., 1997; Lopez et al., 1997; Nakayama et al., 1997), and functional analysis (e.g. phagocytosis) (Hinsch & Hunte, 1990; Tripp, 1992; Mourton et al., 1992; Fryer & Bayne, 1996; Mortensen & Glette, 1996). Flow cytometry represents a rapid technique applicable to both morphological and functional studies of cells in suspension. While the measurements based on autofluorescence provide information on cell morphology, the analyses with fluorescent markers including labelled antibodies, offer data on phenotyping and cell functions. As a result, its application has greatly contributed to the investigation of immunocyte functions and differentiation in vertebrates (Stewart et al., 1986; Rothe & Valet, 1988; Ashmore et al., 1989; Koumans-van Diepen et al., 1994; Rombout et al., 1996; Caruso et al., 1997). Some authors studied oyster haemocyte populations by flow cytometry based on cellular autofluorescence (Friedl et al., 1988; Fisher & Ford, 1988; Ford et al., 1994). However, no analysis using specific monoclonal antibodies has been reported to date. In this study, a protocol for studying European flat oyster, Ostrea edulis, haemocytes by flow cytometry using a monoclonal antibody specific for granulocytes and an indirect immunofluorescence technique have been developed. European flat oysters, Ostrea edulis, 7-9 cm in shell length were obtained from shellfish farms in Marenne Oléron bay (Charente Maritime, France) on the French Atlantic coast. All individuals were purchased just before each experiment and processed without any previous treatment.     

Index of new names of syntaxa published in 1992

The present work collects the new names of syntaxa (in the sense of the Code of Phytosociological Nomenclature,Barkman et al. 1986) above subassociation, rank found in the literature received by the Library of the Conservatoire et Jardin botaniques in Geneva. For the year 1992, 658 names have been listed. For each one of them, an appreciation about its validity is given relating to the Code of Phytosociological Nomenclature. Fifteen names are given in addition to the Indexes 1987, 1990 and 1991 (Theurillat & Moravec 1990, 1993, 1994).     

饲养条件下川金丝猴群中主雄的移除和替换对社群行为的影响

在上海野生动物园对一群半散养的川金丝猴进行了为期一年的行为学研究。在此期间,猴群中发生了4起家庭主雄被移除和替代事件和一个雌性群因繁殖需要引入一个成年雄猴的事件,该过程在饲养条件下首次被完整记录。观察发现,繁殖群中,在家庭主雄猴的健康状况良好期间,群中各雄性成员间的社会等级关系相当稳定,很少变动。主雄猴有效地控制着群体的秩序,并严格地看护着其家庭中的雌猴免受其他雄猴的侵扰,而且它也很少对其他低序位雄猴主动攻击。全雄群中则再由一个高序位雄猴控制其他低序位雄猴。疾病、衰老、前主雄猴的存在以及被饲养人员从群中移除进行治疗等都可能引起猴群社会发生很大动荡,尤其是全雄群中各雄猴的社会等级序位发生剧烈改变,甚至发生家庭主雄的替代。在本报道中,人为因素在主雄替代过程中起着主要作用。主雄替代一旦成功,新主雄会把原主雄赶入全雄群,攻击追撵其他低序位雄猴,并彻底与全雄群完全脱离。对于每一个新主雄,家庭中的雌猴对其的接纳表现出明显的选择倾向。雌性性选择可能是野生猴群中新家庭群建立一种内在基础机制,同时提示偷配发生的可能性。     

Role of ICAM-3 in Intercellular Adhesion and Activation of T Lymphocytes

The immune system requires a fine regulation of intercellular communication for its normal function. There are several regulated molecular pathways involved in leukocyte cell interactions (Springer, 1990; Hynes, 1992). Among them, the interaction of the leukocyte integrin LFA-1 (CDlla/CD18) with its ligands provides multiple accessory adhesion signals of capital importance during different functions of the immune response, such as antigen presentation (Harding and Unanue, 1991), T-B lymphocyte interaction (Moy and Brian, 1992), cellular cytotoxicity (Makgoba et al., 1988; Altmann et al., 1989; Davignon et al, 1981; Akella and Hall, 1992), allogenic and autologous mixed lymphocyte reactions (Bagnasco et al., 1990) and recirculation and homing of lymphocytes through tissue endothelium (Hamann et al., 1988; Pals et al, 1988).     

Targeting of proteins into the peroxisomal matrix

Summary During the last few years much has been learned regarding signals that target proteins into peroxisomes. The emphasis in the near future will undoubtedly shift towards the elucidation of the mechanism of import. The use of mammalian and yeast cells deficient in peroxisome assembly and/or import (Zoeller & Raetz, 1986; Erdmann et al., 1989; Cregg et al., 1990; Morand et al., 1990; Tsukamoto, Yokota & Fujiki, 1990) should provide a handle on the genes (Erdmann et al., 1991; Tsukamoto et al., 1991) involved in these processes. This will have to be coupled with further development of in vitro systems which will permit the dissection of the steps in the translocation of proteins into peroxisomes. Though some progress has been made in the development of such assays (Imanaka et al., 1987; Small et al., 1987, 1988; Miyazawa et al., 1989), the fragility of peroxisomes and the absence of biochemical hallmarks of import (such as protein modifications or proteolytic processing) have hindered progress. Since peroxisomes exist in the form of a reticulum in mammalian cells (Gorgas, 1984), all peroxisome purification schemes (from mammalian cells at least) must undoubtedly rupture the peroxisomes, which then reseal to form vesicular structures. Additionally, the reliance on the latency of catalase alone as a major criterion for the integrity of peroxisomes ignores the fact that many other matrix proteins leak out of peroxisomes at vastly different rates during purification of the organelles (Thompson & Krisans, 1990). In view of these problems, the development of peroxisomal transport assays with semi-intact cells would also constitute an important advance. It is very likely that in the next few years we will witness some major advances in our understanding of the mechanism by which proteins enter this organelle.I would like to thank all the members of my lab and my collaborators, past and present, whose hard work provided the material for this review. This work has been supported by grants from the March of Dimes Foundation (#1081) and the NIH (DK41737).     

Role of ICAM-3 in Intercellular Adhesion and Activation of T Lymphocytes

The immune system requires a fine regulation of intercellular communication for its normal function. There are several regulated molecular pathways involved in leukocyte cell interactions (Springer, 1990; Hynes, 1992). Among them, the interaction of the leukocyte integrin LFA-1 (CDlla/CD18) with its ligands provides multiple accessory adhesion signals of capital importance during different functions of the immune response, such as antigen presentation (Harding and Unanue, 1991), T-B lymphocyte interaction (Moy and Brian, 1992), cellular cytotoxicity (Makgoba et al., 1988; Altmann et al., 1989; Davignon et al, 1981; Akella and Hall, 1992), allogenic and autologous mixed lymphocyte reactions (Bagnasco et al., 1990) and recirculation and homing of lymphocytes through tissue endothelium (Hamann et al., 1988; Pals et al, 1988).     

Microbial carboxylic ester hydrolases (EC 3.1.1) in food biotechnology

Ester linkages between carboxylic acid groups and hydroxyl groups are basic to the structure of carboxyesters and lipids, and occur commonly as modifications of polysaccharide molecules. Microorganisms produce enzymes which hydrolyse the carboxylic ester linkages in substrates which are being utilized for growth. Such esterase reactions are frequently easily reversible, depending on the concentration of reactants or availability of water. The importance of esters as flavour compounds has resulted in the selection of yeast strains which produce esters in beverage fermentation. The synthetic potential of triacylglycerol lipases (EC 3.1.1.3) has been exploited by use of the purified enzymes in environments of low water activity. The techniques of molecular biology facilitate analysis of the homology between carboxylesterase enzymes and a detailed knowledge of structure and specificity provides the opportunity to modify enzymes to suit particular applications in biotechnology.
Esterase activity can be assayed conveniently by using synthetic chromogenic esters of naphthol or nitrophenol. Naphthyl and nitrophenyl acetates are readily hydrolysed by a wide range of enzymes including lipases (Hofelmann et al. 1985; Brahimi-Horn et al. 1990; Gilbert et al. 1991), serine protease (Klapper et al. 1973) and acetylxylan esterase (Lee et al. 1987). Electrophoretic separation followed by detection using chromogenic esters has demonstrated polymorphism of esterase enzymes and has been used to type strains of bacteria (Goullet & Picard 1990, 1991; Picard & Goullet 1990) but was less discriminating with yeasts (Campbell et al. 1972) and edible mushrooms (Itavaara 1988).     

Extracting DNA from the gut microbes of the termite (Zootermopsis nevadensis)

Termites are among the few animals known to have the capacity to subsist solely by consuming wood. The termite gut tract contains a dense and species-rich microbial population that assists in the degradation of lignocellulose predominantly into acetate, the key nutrient fueling termite metabolism (Odelson & Breznak, 1983). Within these microbial populations are bacteria, methanogenic archaea and, in some ("lower") termites, eukaryotic protozoa. Thus, termites are excellent research subjects for studying the interactions among microbial species and the numerous biochemical functions they perform to the benefit of their host. The species composition of microbial populations in termite guts as well as key genes involved in various biochemical processes has been explored using molecular techniques (Kudo et al., 1998; Schmit-Wagner et al., 2003; Salmassi & Leadbetter, 2003). These techniques depend on the extraction and purification of high-quality nucleic acids from the termite gut environment. The extraction technique described in this video is a modified compilation of protocols developed for extraction and purification of nucleic acids from environmental samples (Mor et al., 1994; Berthelet et al., 1996; Purdy et al., 1996; Salmassi & Leadbetter, 2003; Ottesen et al. 2006) and it produces DNA from termite hindgut material suitable for use as template for polymerase chain reaction (PCR).     

HLA class I nucleotide sequences, 1992

The HLA class I sequences included in this compilation are taken from publications listed in the papers: Nomenclature for factors of the HLA system, 1991 (Bodmer et al. 1992); Nomenclature for factors of the HLA system, 1990 (Bodmer et al. 1991); and Nomenclature for factors of the HLA system, 1989 (Bodmer et al. 1990). Due to the increased number of sequences we have only included sequences for exons 2, 3, and 4 in this compilation. Where discrepancies have arisen between reported sequences, the original authors have been contacted where possible, and necessary amendments to published sequences have been incorporated into this alignment. Future sequencing may identify errors in this list and we would welcome any evidence that helps to maintain the accuracy of this compilation. In the sequence alignments, identify between nucleotides is indicated by a hyphen (-). An unavailable sequence is indicated by a period (.). Gaps in the sequence are inserted to maintain the alignment between different alleles showing variation in amino acid number. *** DIRECT SUPPORT *** A4903038 00002     

The DY sub-region of the sheep MHC contains an A/B gene pair

The major histocompatibility complex (MHC) class II region of ruminants appears to have a structure broadly similar to that of the human class II or HLA-D region. Restriction fragment length polymorphism (RFLP) studies of class II genes in cattle (Andersson et al. 1988; Anderson and Rask 1988; Sigurdardottir et al. 1988, 1991 b), and in sheep (Scott et al. 1987), have provided an estimate of the number and type of class II genes in these species. The subsequent cloning and sequencing of sheep and cattle class II genes (Muggli-Cockett and Stone 1989; Groenen et al. 1990; van der Poel et al. 1990; Andersson et al. 1991; Scott et al. 1991 a, b; Ballingall et al. 1992; Sigurdardottir et al. 1991 a, 1992), have demonstrated that they are highly homologous to their human counterparts. Of more interest, therefore, are loci within the ruminant MHC which differ from the HLA class II region.Three distinguishing features of the ruminant class II region described to date are, firstly, the apparent absence of a DP-like isotype, secondly, the variability in the number of DQ genes between haplotypes (Andersson and Rask 1988), and thirdly, the presence of class II genes presumed to be unique to the ruminant (Andersson et al. 1988). The presence of two such genes, designated DYA and DYB, was deduced from RFLP studies of cattle DNA. These genes were shown to segregate together with the DOB gene in one region separated by a recombination distance of 17 cM from the region which contains the DQA, DQB, DRB, DRA, and C4 loci (Andersson et al. 1988). Subsequently, Bota-DYA was cloned from a phage library and sequenced (van der Poel et al. 1990; Acc. Nos. m30119 and m30118). The sequence of part of a similar gene in the goat, obtained by PCR by using primers derived from the cattle sequence, has recently been reported (Mann et al. 1993; Acc. No. m94325). However, there has been no report of the cloning of a B gene partner for the DYA gene. A novel cattle class II B gene designated Bota-DIB was cloned from a phage library and sequenced by Stone and Muggli-Cockett (1990). This was shown to be a single copy gene of limited polymorphism, which on the basis of RFLP analysis was probably not Bota-DYB but did appear to be distinct from other known cattle class II genes. The species distribution of this B gene was shown to be restricted to Cervidae, Giraffidae, and Bovidae (Stone and Muggli-Cockett 1993). However, it is not known whether any of these novel genes are functional.Expressed human class II genes usually occur as A/B gene pairs situated close to each other on the chromosome. This is also the case with Bota-DQ genes (Groenen et al. 1990) and Ovar-DQ genes (Deverson et al. 1991; Wright and Ballingall 1994). We used the techniques of cosmid cloning and DNA-mediated gene transfection to determine whether there is a sheep equivalent of the Bota-DYA gene, whether there is a DYB gene partner, and whether there is a protein product.A cosmid library was constructed from DNA prepared from a Finnish Landrace ram. The library was screened with Ovar-DQA, Ovar-DQB, HLA-DQA, and HLA-DQB gene probes at low stringency. A cosmid clone, 365, was obtained which hybridized weakly to both the Ovar gene probes. Restriction maps of the clone were produced for the enzymes Eco R1, Bam HI, Hin dIII, Sac I and Sma I. When the maps were compared to those published for the phage clones containing the Bota-DYA (van der Poel et al. 1990) and the Bota-DIB gene (Stone and Muggli-Cockett 1990), there was an imperfect match (Figure 1 shows the Eco RI maps). However, the sequence data for the A and B genes in cosmid 365 are more convincing. The sequences of exons 2 and 3 of the A gene in cosmid 365 and the Bota-DYA gene, together with the partial sequence from the third exon of the Cahi-DYA gene are shown in Figure 2 A. The predicted amino acid translations of these genes together with those of other published sheep MHC class II A genes are shown in Figure 2 B. The A gene in cosmid 365 had all the salient features of an MHC class II A gene. It showed a high sequence similarity to the cattle and caprine DYA genes and much less so to the Ovar-DRA gene (Ballingall et al. 1992; Acc. No z11600) and the Ovar-DQA1 and DQA2 (Scott et al. 1991 a; Acc. Nos. m33304 and m33305), as detailed in Table 1. The cosmid A gene showed low sequence similarity to the sheep DNA (formerly DZA) gene (unpublished observations). The A gene described here is clearly the sheep homologue of the Bota-DYA gene.The sequences of the second, third, and fourth exons of the B gene in cosmid 365 are shown in Figure 3 A together with those of the Bota-DIB gene (Stone and Muggli-Cockett 1990). Unfortunately, the presence of a Bam HI site in exon 2 of the sheep gene caused a truncation at this point, during the cloning procedure and so a part of exon 2, the whole of exon 1, and all the upstream regulatory elements were missing. The predicted amino acid translations of exons 2, 3, and 4 are shown together with those of an Ovar-DQB (Scott et al. 1991 a; Acc. No. m33323) and an expressed Ovar-DRB gene (Ballingall et al. 1992; Acc. No. z11522) in Figure 3 B.     

Cloning and nucleotide sequence of the structural gene encoding for human tryptophanyl-tRNA synthetase.

A structural gene encoding bovine (b) tryptophanyl-tRNA synthetase (WRS) has recently been cloned and sequenced [Garret et al., Biochemistry 30 (1991) 7809-7817]. Using part of this sequence as a hybridisation probe we have cloned and sequenced a structural gene encoding human polypeptide highly homologous with two mammalian proteins, bWRS [Garret et al., Biochemistry 30 (1991) 7809-7817; EMBL accession No. X52113] and rabbit peptide chain release factor [Lee et al., Proc. Natl. Acad. Sci. USA 87 (1990) 3508-3512]. Identification of the sequence encoding a human WRS is based on (i) the presence of 'HIGH' and 'KMSKS' structural motifs typical for class-I aminoacyl-tRNA synthetases [Eriani et al., Nature 347 (1990) 203-206]; (ii) coincidence of the number of SH groups per subunit estimated experimentally [Muench et al., Science 187 (1975) 1089-1091] and deduced from the cDNA sequence (six in both cases); (iii) close resemblance of two WRS polypeptides sequenced earlier [Muench et al., Science 187 (1975) 1089-1091] and the predicted structure in two different regions.     

Effects of Endotoxin Contaminated FSH-preparations in Heifers

Superovulation is one important step in embryo transfer. By administration of gonadotropins a multiple ovulation is induced. Several FSH-preparations for superovulation are commercially available. Most of these consist of extracts from pituitary glands from slaughtered farm animals. According to some studies (Yagoda et al. 1990a,b), drugs can easily be contaminated with endotoxins. Endotoxins are commonly found in the environment, for example in water and silage, and in medical preparations (Yagoda et al. 1990b). Endotoxins can have several effects on animals and on human beings. They can cause endotoxaemia with effects like fever, ruminai stasis, release of prostaglandins, leukopenia and decrease of the plasma levels of calcium, zinc, iron and bile acids (Aiumlamai 1991). The severity and range of the effects caused by endotoxin are very dose-dependent. Animals receiving a low dose of endotoxin may not show the clinical signs of endotoxaemia, but can still have subclinical changes like leukopenia, prostaglandin release, mild hypocalcaemia and decreases in the plasma levels of zinc and iron (Yagoda et al. 1990b, Kindahl & Aiumlamai 1991). For humans, 5 EU/kg bodyweight is considered to be the threshold dose for appearance of clinical effects. (Anon. 1987).