The front of the incisors is covered with thick protective layers of enamel. Which best describes the dentition of lagomorphs? Additionally, rabbits and rodents are both found all over the world. How many photons are contained in a flash of green light (525 nm) that contains 189 kj of energy? High mortality associated with an outbreak of hepatitis E among displaced persons in Darfur, Sudan. Furthermore, they did not see a considerable difference in the gross lesions either in gilts, fetuses, or piglets. ; Plant, S.L. ; Caudill, J.D. Didn't find what you need? However, almost 30 percent of all lagomorph species are recognized as endangered species, including four pikas, seven hares, seven cottontails, and seven other rabbits. They demonstrated that the imbalance of the Th1/Th2 immune condition in HEV-infected mice could be related to the elevated frequency of miscarriage. ; Purdy, M.A. In addition, they have a large digestive system, like that of horses. They use their sharp incisors to gnaw food, excavate burrows, and defend themselves. A novel genotype of hepatitis E virus prevalent among farmed rabbits in China. Which two familys represent over half of all rodent species? ; Emerson, S.U. The Rodentia (rodent) is the largest group of mammals, with 1500 of them being rodents (out of 4000 mammals). Avian reproductive anatomy, physiology and endocrinology. While this can also occur in rodents, its less pronounced or appears non-existent. From barnyard to food table: The omnipresence of hepatitis E virus and risk for zoonotic infection and food safety. The six pregnant rabbits infected with HEV showed persistent fecal virus excretion from as soon as 3 dpi until their death or until the experiment ended. Through these, the interactions between seeds and small rodents or lagomorphs are not exclusively positive (seed dispersal) or negative (seed predation), but located at some point along a mutualismantagonism continuum, which makes food-hoarding animals conditional mutualists (Theimer, 2005, Gmez et al., 2019). Cossaboom, C.M. lagomorph, (order Lagomorpha), any member of the mammalian order made up of the relatively well-known rabbits and hares (family Leporidae) and also the less frequently encountered pikas (family Ochotonidae). ; Woolcock, P.R. Lai, F.; Chen, Q. Humanized Mouse Models for the Study of Infection and Pathogenesis of Human Viruses. they have 2 specifically designed upper and lower incisor teeth What is unique about rodent teeth? Ticehurst, J.; Rhodes, L.L., Jr.; Krawczynski, K.; Asher, L.V.S. The primary difference among placental types is in the number of cell layers in the interhaemal area and the ease with which the transfer of macromolecules between the maternal and fetal blood occurs, making it an important factor with respect to the difference in placental permeability between animal species. ICDDRB. ; Yarbough, P.O. Purdy, M.A. Schumacher, A. Ma, H.; Zheng, L.; Liu, Y.; Zhao, C.; Harrison, T.J.; Ma, Y.; Sun, S.; Zhang, J.; Wang, Y. Although they're very popular pets, many people mistakenly believe rabbits belong to the rodent family. Feature papers represent the most advanced research with significant potential for high impact in the field. Dekel, N.; Gnainsky, Y.; Granot, I.; Racicot, K.; Mor, G. The role of inflammation for a successful implantation. Both are rodents but they have some genetic differences rats have 21 pairs of chromosomes and mice have 20 chromosomal pairs. ; Lu, F.M. However, the significant differences in physiology from mammals and resistance to infection with mammalian HEV make the avian HEV model difficult for its use for pathogenesis studies and to stand as an ideal model for HEV pregnancy mortality (, Although not a complete animal model system, placenta cell-derived models, including organoids, can be given consideration for modeling HEV pathogenesis during pregnancy. Most rodents are small animals with robust bodies, short limbs, and long tails. However, no ovary sample showed negative strands of HEV RNA. Rodent ; Khudyakov, Y.E. In the US, reports suggest that 71% of chicken flocks and 30% of individuals are infected by avian HEV [. Mutualistic Fermentative Digestion in the Gastrointestinal To investigate whether HEV infection could produce any pregnancy defects, HEV-infected (group1) and non-infected (group 2) female rabbits were permitted to copulate with healthy male rabbits. ; Tomasi, T.B. Whether you have concerns about your dog, cat, or other pet, trained vets have the answers! Yang, W.; Chen, S.; Mickael, H.K. ; Lee, J.B.; Park, S.Y. This review describes many of the current HEV animal model systems and the strengths and weaknesses of each as they apply to HEV pregnancy-associated mortality. https://doi.org/10.3390/microorganisms11030618, Yadav, Kush Kumar, and Scott P. Kenney. From one week prior to the virus injection to 5 weeks post-injection, embryonated eggs were collected regularly from the above-mentioned group 3 chickens. The first fossil record of mammals with lagomorph-like characters is from the Paleocene Epoch (65 to 54.8 million years ago), a time during which many mammalian orders diversified. Most species of rodents have hairless limbs and tails, which is different from lagomorphs. Rodents can be found on all continents except Antarctica. ; Govindarajan, S.; Shapiro, M.; Gerin, J.L. Studies in which rabbits were experimentally inoculated with human strains of gt3 HEV confirmed seroconversion but were unsuccessful in demonstrating replication and fecal shedding [, In summary, the rabbit model is currently the best HEV model for studying pregnancy mortality. ; Bazer, F.W. Chen, W.; He, B.; Li, C.; Zhang, X.; Wu, W.; Yin, X.; Fan, B.; Fan, X.; Wang, J. Real-time RT-PCR for H5N1 avian influenza A virus detection. While the tissue host tropism of HEV can be identified and innate immune responses characterized cells in a dish, these were unable to provide a complete picture of the human bodys response to HEV infection. The molecular epidemiology of hepatitis E virus infection. Arankalle, V.A. Surprisingly, inoculated gilts/piglets showed no HEV-related clinical signs/fever. WebRabbits do not belong to the Rodentia order, they are lagomorphs (Lagomorpha order). Both rabbits and rodents each have two lower incisors. Arankalle, V.A. The duration of HEV infection, as characterized by fecal virus excretion varied from 6 weeks post-inoculation (wpi) to 15 wpi (experiment ends). ; Fichorova, R.N. ; Burghardt, R.C. In addition, rodents only have tooth enamel on the front of their teeth, which usually has yellowish or orange tones. ; Purcell, R.H.; Halbur, P.G. Also, While there are many similarities between these two groups of animals, they are distinct in a number of important ways. Rabbits are different from rodents in several ways. Aria's Ask and Answer! A distinctive feature setting lagomorphs apart from rodents is the presence of a second pair of peglike incisors set directly behind the large, continuously growing pair in the upper jaw. Lagomorphs possess a moderately fused postorbital process to the cranium, unlike other small mammals. ; Purcell, R.H. The most noticeable feature of these two types of mammals is the continuously growing large chisel-shaped incisors and the distinct diastema between the incisors and the cheek teeth. Due to the presence of these incisors, rodents and lagomorphs have gained the ability of gnawing. There are approximately 1,500 species of mammals alive today. ; Read, D.H.; Meng, X.J. ; Meng, X.J. Our editors will review what youve submitted and determine whether to revise the article. Chirohepevirus from Bats: Insights into Hepatitis E Virus Diversity and Evolution. Pollock, C.G. The lifespan of wild rabbits: how long d Are Rabbits Mammals? Lagomorphs are herbivores and feed on grasses, leaves, seeds, bark, and other plant matter. Izopet, J.; Dubois, M.; Bertagnoli, S.; Lhomme, S.; Marchandeau, S.; Boucher, S.; Kamar, N.; Abravanel, F.; Guerin, J.L. ; Toth, T.E. They have a pair of sharp, chisel-like upper and lower incisors that are continuously growing! Teo, C.G. Arankalle, V.A. Unlike our teeth, these incisors dont have roots, and they never stop growing! WebWhat are the Similarities Between Rodents and Lagomorphs? Overall, while there are many similarities between these two groups of animals, they are distinct in a number of important ways. Here we provide a review of rodent- and lagomorph-mediated seed dispersal based on approximately 600 papers found in an extensive literature search. Khuroo, M.S. ; Tan, C.K. An immune clock of human pregnancy. ; Xu, L.; Xia, Y.; Cong, C.; Zhang, Y.; Qian, Z.; Li, T.; Wei, D.; et al. ; Chiu, T.H. Rodent tooth morphology - Rodents only have enamel on front side of teeth = allows the dentin to be worn away and therefore sharpened - Can close mouth behind incisors = shovel dirt w/o getting in mouth **enamel on one side and ever growing Briefly, the positive/negative HEV RNA and HEV ORF2 antigen were identified in the rabbits brain, heart, lung, stomach, intestine, kidney, and placenta [, In 2017, An et al. ; Poleschuk, V.F. Hepatitis E and pregnancy: Understanding the pathogenesis. demonstrated miscarriage, non-pregnancy, and uterine damage in HEV gt4 (KM01)-infected BALB/c mice after copulation with healthy males. Sridhar, S.; Teng, J.L.L. As the trimester continues, the external layer of the embryo merges with the endometrium, and the placenta is formed. lagomorphs have 4 upper incisor teeth What makes lagomorphs different from rodents? Rab, M.A. ; Orosz, S.E. For starters, rabbits are not actually rodents they are lagomorphs, along with hares and pikas. Breeding & Reproduction Guide, What Smells Deter Cats from Peeing? Li, M.; Li, S.; He, Q.; Liang, Z.; Wang, L.; Wang, Q.; Wang, L. Hepatitis, E-related adverse pregnancy outcomes and their prevention by hepatitis E vaccine in a rabbit model. Lagomorphs proverbially are known for their high rates of reproduction, and many species produce many large litters per year. - Telomerase = rebuilds the protective caps on chromosomes and this process normally decreases with age leading to cancer, - Rodents only have enamel on front side of teeth = allows the dentin to be worn away and therefore sharpened, - Form is successful & independently evolved in many lineages, Two main groups of rodents are based on jaw morphology. No, rabbits are not rodents. Seroconversion to anti-HEV antibodies occurred at 37 wpi except for one rabbit that demonstrated no seroconversion. Takaki, H.; Oshiumi, H.; Shingai, M.; Matsumoto, M.; Seya, T. Development of mouse models for analysis of human virus infections. ; Purcell, R.H.; Emerson, S.U. Legrand-Abravanel, F.; Kamar, N.; Sandres-Saune, K.; Garrouste, C.; Dubois, M.; Mansuy, J.M. This chapter covers studies dealing with exposure and effects of environmental contaminants on rodent and lagomorph species, including pesticides When it comes to the anatomy of their limbs, lagomorphs have five toes on their front legs and four toes on their back legs. In 2018, Knegendorf et al. In addition to the difficulties working with HEV, pregnancy is a very complicated biological process with an elaborate interplay between many different host systems, including hormones, cardiovascular, kidneys, respiratory, gastrointestinal, epithelial, liver, metabolic, immune, and others. However, despite how well known this animal is, we have to clarify quite a common mistake that people make: rabbits arent rodents. ; Meunier, J.C.; Saliou, J.M. Small mammals such as rodents and lagomorphs exhibit extremely rapid foetal and neonatal growth rates and thus already have very short gestation periods (Swihart 1984; Wilson et al. Their fast and prodigious growth and short reproductive cycles make them ideal for performing large numbers of experiments quickly. Lagomorphs are all herbivores. Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for Also, their habitats are What is the difference between lagomorphs and rodents? For example, a rat will have four fingers on their front limbs and five on their hind limbs. Get a Britannica Premium subscription and gain access to exclusive content. Lee, G.H. The key difference between rodents and lagomorphs is that rodents have a double-layered, pigmented layer of enamel which cover only the front part of incisors A historical lack of ability to efficiently propagate the virus in tissue culture models has led to many molecular aspects of the viral lifecycle being understudied. They noted that HEV was capable of completing its viral life cycle in placental-derived cells (JEG-3). Sequence data suggests big liver and spleen disease virus (BLSV) is genetically related to hepatitis E virus. It tends to be very clean, which makes them a great choice for a family pet and even as a house pet. (This article belongs to the Special Issue. Learn more. Their pregnancy status was determined by both a rise in serum progesterone and the palpation of embryos performed by professional breeders. Our dataset supports the same basic phylogenetic structure for Mammalia and Glires (figure 4; electronic supplementary What is the difference between rodents and lagomorphs? Evidence of extrahepatic sites of replication of the hepatitis E virus in a swine model. Immunology of the maternal-fetal interface. PrabhuDas, M.; Bonney, E.; Caron, K.; Dey, S.; Erlebacher, A.; Fazleabas, A.; Fisher, S.; Golos, T.; Matzuk, M.; McCune, J.M. For more information, please refer to Krawczynski, K.; Meng, X.J. ; Rozanov, M.N. Care needs to be taken when choosing established cell lines to ensure that specific cells are reactive to exogenous stimuli such as hormones. Sayed, I.M. However, they showed that avian HEV could successfully propagate into 9-day-old embryonated chicken eggs when inoculated IV with 100 GE of avian HEV. Both groups of animals are small in size, have big eyes, and are mainly herbivorous. Rabbits and hares characteristically have long ears, a short tail, and strong hind limbs that provide a bounding locomotion. Anti-HEV IgG was detected in all the infants, and HEV RNA was detected in five. Yu, W.; Hao, X.; Li, Y.; Yang, C.; Li, Y.; He, Z.; Huang, F. Vertical transmission of hepatitis E virus in pregnant rhesus macaques. This means that they have different characteristics and needs than rodents do. In contrast, lagomorphs are another group of mammals that have two pairs of ever-growing rootless incisor teeth. ; et al. Notably, the major extrahepatic replication sites of HEV were determined to be lymph nodes and the intestinal tract [, In 2001, Halbur et al. Uncovered forums do not intend to provide veterinary advice. In addition, they mentioned that the control groups were negative for anti-HEV antibodies and fecal HEV RNA and had normal ALT and AST levels. rodents and lagomorphs Outbreak of hepatitis E in a low income urban community in Bangladesh. difference between lagomorphs While there are many differences between rabbits and rodents, there are also some similarities. ; Brito, C.; Alves, P.M. Bioengineered liver cell models of hepatotropic infections. Corneillie, L.; Banda, D.H.; Meuleman, P. Animal Models for Hepatitis E virus. - they replace the protective caps on their chromosomes throught their whole lives, therefore preventing cancer and living longer. ; Meng, X.J. What is the difference between lagomorphs and rodents? These teeth grow continuously, but the second pair of incisors is small. Ectopic Expression of Genotype 1 Hepatitis E Virus ORF4 Increases Genotype 3 HEV Viral Replication in Cell Culture. ; Meng, X.J. They concluded that avian HEV could enter the egg white (typically 10 mL egg white is present in chicken eggs) with a relatively high dose; however, no virus was detected in the chicks, signifying that avian HEV in eggs could not live through the initial embryonation phase (19 days of embryonation) [, The chicken model was able to evaluate vertical transmission and the causes of infertility, as seen with drops in egg production. Liver tissue histopathology in pregnant rabbits with HEV infection was also conducted and demonstrated bridging necrosis or piecemeal necrosis and the infiltration of inflammatory cells via hematoxylin and eosin (HE) staining. Rabbits and rats come from two different families and cant interbreed. The lengthy viremia and fecal shedding in rHEV-infected rabbits resembled human chronic HEV infection. ; Debing, Y.; Brown, R.J.P. Rabbits Aren't Rodents! - My Animals Chronic inflammatory cell infiltrations and obvious portal fibrosis seen during histopathology were the indicators of chronic HEV infection in rabbits. ; Dama, B.M. ; Song, B.; Nimgaonkar, I.; Hrebikova, G.; Contreras, J.E. ; Elvinger, F.; Toth, T.E. performed a comparative pathogenesis study of infected pigs with HEV recovered from a pig and a human from the above groups. ; Prasad, S.R. Another difference is that rodents are omnivores and, therefore, eat everything. Rayis, D.A. They are characterized by their long, thin tails, big eyes and small size. Clinical course and duration of viremia in vertically transmitted hepatitis E virus (HEV) infection in babies born to HEV-infected mothers. Animal models of human placentationA review. **What are the shared features and differences between the two orders of rodentia and Lagomorpha? ; et al. Experimental infection of pregnant gilts with swine hepatitis E virus. Montella, M.; DArena, G.; Crispo, A.; Capunzo, M.; Nocerino, F.; Grimaldi, M.; Barbieri, A.; DUrsi, A.M.; Tecce, M.F. However, there are also several species that breed only once per year or have only very small litters. Similarly, pigs injected with RNA transcripts from clone pSHEV-1, which had three non-silent mutations in the ORF2 capsid gene, seroconverted late with delayed fecal virus shedding and had unnoticeable viremia [, Thus, subclinical courses of infection were reported in pigs. Immune mechanisms at the maternal-fetal interface: Perspectives and challenges. The further development of small animal models, such as the BALB/c mouse model, to determine if gt1 or gt2 HEV pathology can be recapitulated is warranted, and provide hope for further small animal model development in the HEV pregnancy mortality field. ; Mensing, T.L. Other common species include beavers, porcupines, squirrels, and capybara. This is because a rabbit has four incisors in the upper jaw (including two non-functional teeth), while rodents only have two. You seem to have javascript disabled. ; Govindarajan, S.; Herbert, R.; St Claire, M.; Elkins, W.R.; Cook, A.; Shaver, C.; Beauregard, M.; Swerczek, J.; et al. What is the difference between rodents and mammals? ; Renou, C. Zoonotic hepatitis E: Animal reservoirs and emerging risks. Lagomorphs differ from rodents in both dentition and jaw structure. ; Emerson, S.U. Although six rabbits were infected with HEV, viremia was observed only in two rabbits, and increases in ALT and aspartate aminotransferase (AST) levels were roughly two-fold higher than the baseline level that was detected in only one rabbit. FJ906895, FJ906888, FJ906896, FJ906893) was performed. Four 810-day-old piglets from each of the six sows that farrowed were necropsied at 46 dpi. ; Bradley, D.W. Computer-assisted assignment of functional domains in the nonstructural polyprotein of hepatitis E virus: Delineation of an additional group of positive-strand RNA plant and animal viruses. Hepatitis E virus replication and interferon responses in human placental cells. ; Kevorkian, Y.B. With only two families and 87 species, order Lagomorpha is not a diverse group of mammals (there are more than 2,000 rodent species), but as native or introduced species they have a nearly worldwide distribution. Gardinali, N.R. ; Waldschmidt, T.J. Estrogen blocks early T cell development in the thymus. Author to whom correspondence should be addressed. Furukawa, S.; Kuroda, Y.; Sugiyama, A. Inflammatory exudates and hemorrhages were apparent upon histopathological examination, suggesting that severe inflammatory responses were seen in the uterus of terminated mice (middle pregnancy). evaluated the replication of strain HB-L3, gt4 swine HEV (90.9% homology to a Beijing human strain) in the ovary and explored structural and molecular alterations stimulated by the intraperitoneal injection of HEV in rabbits. Rodents and Lagomorphs Leblanc, D.; Ward, P.; Gagne, M.J.; Poitras, E.; Muller, P.; Trottier, Y.L. Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm. The evolution of rodents and lagomorphs. Lagomorphs | Lagomorpha Dimensions & Drawings Naked viruses that arent always naked: Quasi-enveloped agents of acute hepatitis. They are found in all parts of the world and are known for their ability to reproduce quickly. Editors select a small number of articles recently published in the journal that they believe will be particularly Additionally, it was interesting to know that pigs developed comparatively more severe and persistent lesions when injected with the US-2 strain of human HEV than swine HEV based on microscopic evaluations. Marek, A.; Bilic, I.; Prokofieva, I.; Hess, M. Phylogenetic analysis of avian hepatitis E virus samples from European and Australian chicken flocks supports the existence of a different genus within the Hepeviridae comprising at least three different genotypes. The timing of the origin and diversification of rodents remains controversial, due to conflicting results from molecular clocks and paleontological data. ; Gregory, A.R. ; Ankavay, M.; Bull, A.; Pillez, A.; Abravanel, F.; Helle, F.; et al. - they are classified as either Sciurognath which have v-shaped jaws or Hystricognath which have a u shaped jaw. Granot, I.; Gnainsky, Y.; Dekel, N. Endometrial inflammation and effect on implantation improvement and pregnancy outcome. Taneja, V. Sex hormones determine immune response. ; Meng, X.J. This means that if you are not prepared for a lot of responsibility, a rabbit may not be the right pet for you. However, all other rabbits that were inoculated with different strains from rabbits, swine, and humans successfully resulted in adverse pregnancy outcomes. ; Foquet, L.; Verhoye, L.; Abravanel, F.; Farhoudi, A.; Leroux-Roels, G.; Izopet, J.; Meuleman, P. Transmission of hepatitis E virus infection to human-liver chimeric FRG mice using patient plasma. Forty-two female rabbits were split into seven groups, with two groups administered with a preventative vaccine and one group with PBS. The infectivity of the orally administered virus was minimal, with only two rabbits displaying fecal shedding and seroconversion [, Interestingly, around 2014, Han et al. One of the best approaches to studying HEV in pregnancy is likely a combinatorial approach that uses the best combination of emerging in vitro and in vivo systems while accounting for the deficiencies that are present in each model. Michelle Provost-Craig, Susan J. Purcell, R.H. Also, Thus, they confirmed that the tissues and organs that were positive for viral RNA (positive strand) in the absence of viral RNA in the serum were an indicator of success for viral RNA replication. Rabbits are also social creatures that enjoy the company of humans or other animals. Lagomorphs are a mammalian class that includes rabbits, hares, and pikas. ; Legters, L.J. These systems can be created from human cells and tissues and mimic in vivo phenomena such as the innate immune response to viral infection and how pregnancy hormones might contribute to infection outcomes. ; Meng, X.J. Fecal HEV RNA was detected from the primary defecation of all newborn rabbits born from infected mothers. Please let us know what you think of our products and services. ; Lim, S.G.; Dan, Y.Y. Tsarev, S.A.; Tsareva, T.S. Rasheeda, C.A. contact@uncoveredforums.com+44 077 6565 0135, We will send you up-to date tips and guide directly to your inbox, The ultimate guide to setting up a rabbit cage, Are Rabbits Mammals? ; Guenette, D.K. Their incisors continue to grow throughout their lives, which is also true of rodents and they have a gap between their incisors and the teeth by their cheeks. Hatched chicks necropsied at 23 days of age were reported as avian HEV positive for bile and liver samples. Another trait of all lagomorphs is their production of two kinds of fecessolid round droppings and soft black greaselike pellets. From 3 to 20 dpi, tissues were found positive for human HEV RNA in inoculated pigs. (US & Worldwide Statistics in 2023). ; Larsen, C.T. ; Wilcox, G.E. Rabbits were infected with a naturally occurring gt3 strain of HEV that also infects humans. Required fields are marked *. All rights reserved. ; Pavri, K.M. ; Wiersma, S.T. The course of hepatitis E virus infection in pigs after contact-infection and intravenous inoculation. The, Role of Placental, Hormones in Mediating Maternal Adaptations to Support Pregnancy and Lactation. Rabbits, hares, and pikas are distinct from rodents in various respects, for example they have four incisor teeth (rather than two) and they are almost completely herbivorous (whereas many rodents also eat meat). While mice have been a workhorse model system for demonstrating many complex biological functions, more study is needed to determine if a truly representative HEV pregnancy model can be established in these animals. ; Halbur, P.G. Recent work has suggested the rabbit model in which rHEV gt3 strains can induce mortality of both the doe and kit, along with recapitulating many facets of HEV pathology, makes it currently one of the best models to utilize for dissecting pregnancy mortality. The two faces of hepatitis E virus. Significant differences between the timing and interplay of these systems are notable between species, and making direct comparisons between animals and humans can be difficult at times. Gouilly, J.; Chen, Q.; Siewiera, J.; Cartron, G.; Levy, C.; Dubois, M.; Al-Daccak, R.; Izopet, J.; Jabrane-Ferrat, N.; El Costa, H. Genotype specific pathogenicity of hepatitis E virus at the human maternal-fetal interface. Hepatitis E virus strains in rabbits and evidence of a closely related strain in humans, France. The soft feces are produced in the cecum and contain up to five times the vitamin content of hard feces; these are reingested (see coprophagy). ; Kamali, S.; Jameel, S. Vertical transmission of hepatitis E virus. ; Toth, T.E. Aghaeepour, N.; Ganio, E.A. Han, J.; Lei, Y.; Liu, L.; Liu, P.; Xia, J.; Zhang, Y.; Zeng, H.; Wang, L.; Wang, L.; Zhuang, H. SPF rabbits infected with rabbit hepatitis E virus isolate experimentally showing the chronicity of hepatitis. Meet Brer Rabbit and Sister Hare Xia, J.; Liu, L.; Wang, L.; Zhang, Y.; Zeng, H.; Liu, P.; Zou, Q.; Wang, L.; Zhuang, H. Experimental infection of pregnant rabbits with hepatitis E virus demonstrating high mortality and vertical transmission.