Eimeria macusaniensis n. sp. (Protozoa: Eimeriidae) of the Alpaca Lama pacos

SYNOPSIS. A new species of coccidium, Eimeria macusaniensis n. sp., is described from the alpaca Lama pacos in Macusani, Peru. The oocysts are ovoid to piriform, 81–107 by 61–80 μ (mean 93.6 by 67.4 μ) with a micropylar cap and elongate ovoid sporocysts 33–40 by 16–20 μ (mean 36.3 by 18.3 μ).     

羊驼毛的结构及其特性研究

为研究羊驼毛的特性并评价羊驼的生产性能,观察了羊驼皮肤和毛的显微结构和超微结构。结果表明:皮肤中皮脂腺很少,这决定了羊驼毛易清洗;毛囊由初级毛囊和大部分复合毛囊组成,因此大部分羊驼毛很细;羊驼毛的髓质比例小于皮质所占比例,而且白毛的髓质与皮质的比例大于有色毛,这决定了羊驼毛轻而具有好的保暖性,且白毛重量轻于有色毛;羊驼毛的皮质细胞具有双层结构,上皮细胞有5层,皮质周围有内、外上皮,这些结构可能使毛避免损伤,并可使黑色素颗粒避免丢失以维持其自然色;羊驼毛的鳞片呈锯齿状并形成裂痕,具有疏水性,因此羊驼毛可以防水。所有这些特点决定了羊驼毛在毛纺工业中是理想的原料。     

New Species of Eimeria (Protozoa: Eimeriidae) from Malaysian Squirrels*

SYNOPSIS. In a survey of 520 squirrels of 19 species from Malaysia, 6 new species of Eimeria were found. Three are described from the subfamily Petauristinae: E. kylopetis n. sp. from the red-cheeked flying squirrel Hylopetes spadiceus; E. aeromysis n. sp. from the large black flying squirrel Aeromys tephromelas; E. malayensis n. sp. from the spotted giant flying squirrel Petaurista elegans. Three are described from the subfamily Sciurinae: E. hippuri n. sp. from the horse-tailed squirrel Sundasciurus hippurus; and E. notati and E. pahangi n. spp. from the plantain squirrel Callosciurus notatus.     

New Species of Eimeria (Protozoa: Eimeriidae) from Malaysian Rats*

SYNOPSIS. Four new species of Eimeria were found in a survey of 255 rats of 14 species in Malaysia. E. tikusi n. sp. and E. edwardsi n. sp. are described from Edwards' rat Rattus edwardsi. The ellipsoidal, single-layered oocysts of E. tikusi average 30.3 by 24.4 μ. A micropyle is absent; a polar granule is present. Ovoid sporocysts average 14.2 by 9.8 μ. A sporocyst residuum and Stieda body are present. The ovoid, 2-layered oocysts of E. edwardsi average 29.1 by 21.8 μ. A micropyle is present; a polar granule is absent. Ellipsoidal to ovoid sporocysts average 14.5 by 6.5 μ. A sporocyst residuum is present; Stieda body is small or absent. E. surifer n. sp. is described from the red spiny rat Rattus surifer. Its ellipsoidal 3-layered oocysts average 34.7 by 24.8 μ. A micropyle is absent; a polar granule is present. The ellipsoidal sporocysts average 15.4 by 9.5 μ. A sporocyst residuum, Stieda body and sub-Stieda body are present. E. sabani n. sp. is described from the long-tailed giant rat R. sabanus. Its ellipsoidal 2-layered oocysts average 28.5 by 21.7 μ. A micropyle is absent; a polar granule is present. The ellipsoidal-to-ovoid sporocysts average 11.9 by 8.0 μ. A sporocyst residuum and Stieda body are present.     

催乳素受体基因与羊驼繁殖性能关系的初探

通过氯仿/异戊醇法制备羊驼血液基因组DNA,采用PCR方法首次扩增出羊驼催乳素受体基因(prolactin receptor gene,PRLR)exon8-exon9序列(GenBank登录号为DQ198164),该片段长度为622bp。通过NCBI blast(http://www.ncbi.nlm.nih.gov/BLAST/)比较,结果表明:该序列包括exon8的82bp、intron8全序列472bp和exon9的68bp。同源性比较发现,羊驼PRLR基因exon8和exon9核苷酸序列与其它哺乳动物的相应区域的同源性特高,均≥92%;同时还发现羊驼exon8引物后第19个碱基为G,而其它哺乳动物(猪除外)均为A,猪则是在羊驼exon8引物后的第34个碱基处由G变为A,通过推导氨基酸序列分析发现,这种单碱基的突变使得羊驼与其它哺乳动物相比,该处的氨基酸由亮氨酸取代了异亮氨酸;在羊驼exon9引物前第22个碱基处也发生了A-G碱基替换现象,但这个碱基的突变发生在密码子的第3个碱基上,编码的氨基酸均为脯氨酸。在这些动物中只有羊驼为单胎动物,羊驼exon8核苷酸序列中A-G的碱基替换并引起编码氨基酸序列发生改变是否与羊驼繁殖性能有关还有待进一步研究。     

FGF5在青年羊驼背部和耳部皮肤中的表达和定位

羊驼是毛用型经济动物,其耳部和背部的毛发品质和生长周期存在差异. 据研究成纤维细胞生长因子5（fibroblast growth factor 5, FGF5）在多种哺乳动物中影响毛发长度. FGF5基因的突变导致小鼠、狗和猫隐性的长发表型,其也参与了家兔绒毛长度的变异. 本实验旨在研究FGF5在青年羊驼皮肤中的表达和定位,以及在羊驼背部和耳部皮肤中的差异比较,探讨其在羊驼毛发生长发育过程中的作用及其相关机制. 实验采用实时荧光定量PCR、Western印迹和免疫组织化学等技术,对FGF5在青年羊驼背部和耳部皮肤中的mRNA、蛋白表达水平和定位进行了研究. 实时荧光定量PCR结果显示,FGF5在青年羊驼耳部皮肤组织中相对基因表达量是羊驼背部皮肤组织的25265倍(P<001); Western印迹结果显示,羊驼皮肤组织粗蛋白提取物中存在与兔抗FGF5多克隆抗体发生免疫阳性反应的蛋白条带,羊驼耳部皮肤平均蛋白表达量显著高于背部;免疫组织化学结果显示,FGF5在羊驼皮肤的毛根鞘,毛母质细胞和毛髓质等部位均表达,根据光密度值得出,该蛋白在羊驼背部和耳部皮肤中的表达差异极显著（P<001）. 试验结果提示FGF5可能抑制了羊驼毛发的生长.     

羊驼性别决定基因sry部分片段的克隆与序列分析

从成年羊驼血液提取基因组DNA,参照哺乳动物sry(sex-determining region on the Y chromosome)基因的同源保守区域设计特异性引物,用PCR技术成功扩增羊驼sry基因的部分片段,且全部实验雄性个体均成功扩增,而雌性个体则无任何特异性片段,说明所扩增基因片段具雄性特异性。对扩增序列所编码蛋白序列分析显示所扩增的片段编码的蛋白序列在哺乳动物sryHMG-box(high mobility group box)蛋白超家族的HMG-box区域,说明扩增的为sry基因片段。用所扩增片段与其他哺乳动物同源序列分析显示,由sry基因构建的系统进化树,与传统的动物分类关系相近,说明由sry基因的HMG-box构建系统树是分析物种亲缘关系的有效工具。     

Extra-Intestinal Stages of Isospora felis and I. rivolta (Protozoa: Eimeriidae) in Cats*

SYNOPSIS. Evidence is presented that Isospora felis and I. rivolta invade the extra-intestinal tissues of cats. Kittens were fed sporocysts of I. felis and I. rivolta. At specific intervals the kittens were killed and suspensions of extra-intestinal tissues were fed to indicator kittens less than a day old. Oocyst production by the indicator kittens within the regular prepatent period was taken as evidence that coccidian stages were present in the inoculum consisting of extra-intestinal tissues of cats. Tissues of kittens infected with I. felis for 5–104 days were infectious to newborn kittens as follows: liver and spleen mixture 3 out of 5 times, mesenteric lymph nodes 4 out of 4 times, brain and muscle mixture 1 out of 5 times, lungs 1 out of 5 times. The prepatent period in kittens consuming oocysts of I. felis was 7-11 days; after consuming extra-intestinal tissues of kittens it was 4–8 days. Distinct coccidian stages unlike those present in the gut were found singly and in groups of 2–15 in lymphoreticular cells of mesenteric lymph nodes of 2 kittens infected for 2–4 days. Tissues of kittens infected with I. rivolta for 5–21 days were infectious to newborn kittens as follows: liver and spleen mixture 3 out of 5 times, mesenteric lymph nodes 1 out of 5 times, brain, muscle and lung mixture none of 5 times. The prepatent period in kittens consuming oocysts of I. rivolta or extra-intestinal tissues of cats was 5–7 days. Coccidian stages occurred singly or in pairs, intracellularly or free in the mesenteric lymph nodes of 3 out of 10 kittens infected for 1–8 days.     

Seven New Eimeria spp. (Protozoa,Coccidia) from Freshwater Fishes of Canada*

Seven new species of Eimeria are described and figured from the freshwater fishes of Ontario and Quebec, Canada. They are Eimeria catostomi sp. n. and E. fernandoae sp. n. from Catostomus commersoni (Lacépède), E. etheostomae sp. n. from Etheostoma exile (Girard), E. hoffmani sp. n. from Umbra limi (Kirtland), E. micropteri sp. n. from Micropterus dolomieui Lacépède E. pungitii sp. n. from Pungitius pungitius (Linnaeus), and E. salvelini sp. n. from Salvelinus fontinalis (Mitchill). Furthermore, 2 new host records and 2 new distribution records for North America are reported for E. anguillae Léger & Hollande, 1922 and E. truttae Léger & Hesse, 1919 respectively. Finally, morphologically similar oocysts found in various cyprinids are regarded as belonging to E. iroquoina Molnar & Fernando, 1974.     

Photoperiodic control of the time of parturition in alpacas (Lama pacos)

Twenty-three mature female alpacas in late gestation in October (spring group) and in January (summer group), were randomly allocated to two treatments. In each season, one group was placed indoors under natural light and the other group was placed in a treatment room which could be totally blacked out to external light and had artificial lights controlled by an automatic time switch. Lights in the treatment room were switched on at 12:00 h and switched off at 02:30 h. Video cameras were used to record the times of parturition. The mean time of parturition for alpaces in the treatment room (16:43 h ± 69 min) was 6 h 23 min later (P < 0.001) than the alpacas in the control room (10:20 h ± 67 min). The mean intervals from sunrise or lights-on to parturition and from sunset or lights-off to parturition were similar for both treatment groups, and there were no effects of treatments on gestation length. The mean interval from the start of the treatments to parturition was shorter (P < 0.001) in the spring group(18 ± 2 days) than in the summer group (36 ± 2 days). In conclusion, the results showed that the time of parturition in alpacas is under photoperiodic control.     

Prevalence of Eimeria macusaniensis (Apicomplexa: Eimeriidae) in midwestern Lama spp

To compare the prevalence of Eimeria macusaniensis among midwestern llamas (Lama glama), alpacas (Lama pacos), and guanacos (Lama guanicoe), feces were obtained from Lama spp. in 10 states between October 1989 and February 1996. Feces were examined by centrifugal flotation in sugar solution (specific gravity--1.28-1.30), and oocysts were quantified by a modified McMaster method. Data were compared by host species and age classifications. Typical oocysts occurred in samples from 28% of 76 herds and 10.4% of 443 animals including 12% of 301 llamas, 7% of 115 alpacas, and 7.4% of 27 guanacos. Prevalence was significantly greater (P = 0.009) in animals < 1 yr of age in comparison to older animals for llams (22.1 v.s. 8.5%) and for all Lama spp. combined (17.1 vs. 8.4%). Fecal oocyst abundance was significantly greater (P = 0.001) in llamas < 1 yr of age in comparison to older llamas (30 vs. 16 oocysts per g of feces). Fecal oocyst intensities did not differ significantly. Prevalence in both age groups of midwestern llamas was greater than previously reported for llamas in the western United States. Prevalence in midwestern alpacas < 1 yr of age was lower than reported for alpacas of similar age in South America, but oocyst intensities were similar. These results indicate that infection with E. macusaniensis is more common in Lama spp. in North America than previously recognized.