Development In Chick Research Articles

The initial stage in the development of the lens capsule in chick and mouse embryos

Electron microscope observations on the first stage of lens capsule development in chick and mouse embryos are described. A process unique to this stage was seen, in the first reduplication (and only the first) of the original single basement membrane, in which “blister-like” projections erupted from the original single basement membrane, and eventually coalesced with each other to form a second layer. The possible significance of this observation is discussed.

Infectivity, Growth, and Development of Leucochloridiomorpha constantiae (Trematoda) in the Chick and on the Chorioallantois

Leucochloridiomorpha constantiae metacercariae grew, attained sexual maturity, and produced eggs containing fully developed miracidia in the bursa of Fabricius of the domestic chick and on the chick chorioallantois. Chicks cloacally exposed to metacercariae remained infected up to 8 weeks although the bursa was still present after 12 and 13 weeks. Following cloacal exposure with metacercariae, a low percentage of worms was recovered from the rectum of chemically bursectomized chicks. Body and testicular growth were greater in chickthan in chorioallantoic worms although as development progressed both demonstrated similar testicular-to-body size ratios. Daily development in the chick and on the chorioallantois has been described through sexual maturity. Chorioallantoic worms became ovigerous and contained eggs with miracidia later than chick worms and frequently produced aberrant eggs and abnormal stages of spermatogenesis, suggesting the chick is a more favorable site for development. Leucochloridiomorpha constantiae (Mueller, 1935) parasitizes the bursa of Fabricius of the black duck, Anas rubripes, and has been maintained in the small intestine of raccoons, and in the bursa of domestic ducks and chicks in the laboratory (Gower, 1938; Allison, 1943; Fried and Harris, 1971). Free metacercariae obtained from the uterus of naturally infected Campeloma decisum snails are suitable for experimental studies since they are easily maintained in the laboratory, infect domestic chicks and the chick chorioallantois, and become ovigerous in these sites within 3 or 4 days. This paper reports studies on infection, growth, and development of this trematode in the chick and on the chorioallantois. MATERIALS AND METHODS As described previously (Fried and Harris, 1971), metacercariae obtained from C. decisum snails were used to infect 1and 2-day-old domestic chicks cloacally and worms were recovered from the bursa. Chicks exposed to 4 to 6 metacercariae were necropsied at intervals from 5 min to 13 weeks to determine infectivity. Growth and development studies were made on worms reReceived for publication 7 September 1971. * Supported in part by a research grant from the Lafayette College Committee on Advanced Study and Research. t Present address: Institute for Pathobiology, Lehigh University, Bethlehem, Pennsylvania 18015. + Present address: Cornell University Medical College, New York, New York 10021. covered daily from 1 to 7 days following exposure of chicks to either 3 or 5 metacercariae. Infectivity was also determined for 14 1and 2-day-old chicks exposed orally to a total of 116 metacercariae (5, 6, or 10 each) in Ringer's and necropsied 3 days later. Chemically bursectomized chicks were hatched from eggs which, on the 3rd day of incubation, had been dipped, pointed end down, into cold 3% testosterone propionate (Nutritional Biochemicals Co., Cleveland, Ohio) in 95% ethanol to a depth of approximately 40 mm for 5 sec (Glick and Sadler, 1961). Infectivity was determined for 14 1and 2-day-old bursectomized chicks exposed cloacally to a total of 94 metacercariae (3 to 17 each) and necropsied at intervals from 4 hr to 3 days. Metacercariae transferred through 3 changes of sterile Ringer's were placed on chorioallantoic membranes of 8to 10-day-old fertile white leghorn eggs (Zwilling, 1959). Eggs which received 5 or 6 metacercariae each were incubated at 37.5 C and flukes were recovered daily from 1 to 8 days postinoculation. Metacercariae, chick-, and chorioallantoic worms were pipetted into hot AFA (Fried, 1962a), stained in Gower's (1939) carmine, cleared in terpineol, mounted in Permount, and used for growth measurements. Worms stained intravitally with neutral red were examined under light coverslip pressure to assess development and observations were also made on Bouin's and Caroy fixed paraffin sections stained with either Harris' hematoxylin or Heidenhain's iron alum hematoxylin and eosin.

Excystation of Metacercariae of Posthodiplostomum minimum minimum Hoffman, 1958, and Their Development in the Chick and on the Chorioallantois

Sexual maturation of trematode metacercariae of Posthodiplostomum minimum minimum from cyprinid fishes occurred within 27 hr in the domestic chick. Excystation of 71.9 and 83.5% of cysts at 37.5 and 41 C, respectively, occurred within 30 min in 0.1% pepsin-Ringer's-HCl-pH 2.5. Excysted metacercariae survived up to 10 days on the chick chorioallantois at 37.5 C, became ovigerous on the membrane at 41 C within 3 days, and chorioallantoic-eggs embryonated. Feeding of flukes on the membrane appeared restricted to the chorionic layer. Various authors (Hunter and Hunter, 1940; Ferguson, 1943; Miller, 1954; Hoffman, 1958) have presented experimental evidence indicating that strigeid metacercariae of Posthodiplostomum minimum (MacCallum, 1921) from centrarchid fishes are physiologically different from those obtained from cyprinids. Because of these differences Hoffman (1958) proposed the subspecies P. minimum minimum for forms from cyprinid and P. minimum centrarchi for metacercariae from centrarchid fishes. Recently, cysts of P. minimum minimum from Notropis volucellus, Notropis sp., and Pimephales notatus became available through the courtesy of Dr. Russell R. Williams, Waynesburg College, Waynesburg, Pa. The purpose of this research was to study excystation of P. minimum minimum metacercariae and their development in the domestic chick and on the chorioallantois. MATERIALS AND METHODS Cysts dissected from minnows in Waynesburg, Pa., and mailed in saline to Easton, Pa., were used upon receipt or within 10 days after storage in Paul's (1960) Ringer's 1:1 at 10 C. Ten or 25 cysts were fed in 1 to 2 ml of Ringer's to each of 34 day-old domestic chicks which were necropsied 1 to 13 days later (Table I). In excystation studies 25 to 50 cysts were placed in petri dishes containing either 30 ml of 0.1% pepsin, 1 to 10,000 (Nutritional Biochemicals Co., Cleveland, Ohio) in Ringer's adjusted to pH 2.5 with HC1, 0.1% pepsin in Ringer's, Ringer's, or Ringer's adjusted to pH 2.5 with HC1, and maintained at 37.5 or 41 C for up to 30 min. Chemically excysted metacercariae transferred through 3 changes of sterile Ringer's (Fried et al., Received for publication 9 April 1970. * Supported in part by NIH Grant AI-06835-04. 1968) were placed on the chorioallantoic membranes of 8to 10-day-old fertile while leghorn eggs (Table II). Eggs incubated at 37.5 and 41 + 1 C were examined 1 to 10 days postincubation. To determine their viability, eggs teased from chorioallantois-flukes or those obtained from membranes were incubated in tap water at room temperature (21 to 23 C) for 12 days. To assess worm development, some excysted metacercariae, chick, and chorioallantois-flukes were stained in Gower's carmine, malachite green, catechol, Fast Red salt B, or hematoxylin and eosin as described previously (Fried and Foley, 1969, 1970). Others were fixed in 7% acetic acid (Cain, 1969) and stained according to the benzidine method of Humason (1967) for the detection of a hemoglobinlike compound. Membranes from which live worms were removed were fixed in 10% neutral buffered formalin and prepared as 8-j, paraffin sections stained with hematoxylin and eosin. Forty excysted metacercariae, maintained 10 per petri dish in 30 ml of Ringer's or Ringer's containing 1 mg/ml glucose and incubated at 37.5 or 41 + 1 C, were used to determine survival and possible development of P. minimum minimum in Ringer's.

Effect of Manganese Upon the Epiphyseal Growth Plate in the Young Chick

IT is well established that manganese is essential for normal bone development in the young chick. Early investigations, designed to study the mechanism of action of this nutrient, indicated that manganese deficiency did not greatly affect calcification. More recent evidence suggests that manganese is required for proper formation of the organic matrix of cartilage and bones. Wolbach and Hegsted (1953) reported that manganese deficiency retarded endochondral bone formation. These authors felt that the skeletal manifestations of perosis resulted from retardation or suppression of epiphyseal cartilage sequences, including matrix formation and cell proliferation, growth and maturation. Evidence that manganese is essential for proper matrix formation was provided by Leach and Muenster (1962) who reported that tissues from manganese-deficient chicks had a reduced chondroitin sulfate content. Of the tissues studied, the epiphyseal plate showed the greatest reduction in this matrix constituent. This report presents further evidence in support of the above observations.

DETOUR LEARNING AND DEVELOPMENT IN THE DOMESTIC CHICK.

DETOUR LEARNING AND DEVELOPMENT IN THE DOMESTIC CHICK.