Pituitary and cerebellum of nude mice.

The anterior pituitary of athymic homozygous "nude" (nu nu) mice shows signs of reduced activity of the acidophilic cells, nuclear volumes of which lag significantly behind normal values. Also there is a significant deficiency in the number of basophilic cells. A similar deficiency is found in the numbers of Purkinje cells of the cerebellum, which in addition also show a reduction in size, as part of an overall reduction of cerebellum size.

Interferon production in athymic nude mice.

Athymic (homozygous nude) mice of a non-inbred stock had relatively little antiviral activity in their serum compared with normal control mice at 4, 6 and 6.5 h after the intraperitoneal injection of Newcastle disease virus. The antiviral activity in the serum had the characteristics of interferon.

Ovarian development in athymic nude mice V. The effects of PMSG upon the numbers and growth of follicles in the early juvenile ovary.

The composition and growth patterns of the ovarian follicle population have been determined in early juvenile athymic nude mice and their phenotypically normal littermates. Nude ovaries contained significantly more primordial follicles and fewer trilaminar follicles at 10 days of age. The rate of growth of the oocyte nucleolus was significantly less than in control ovaries.

Ovarian development in athymic nude mice. IV. The effect of PMSG and oestradiol on the growth of the oocyte and follicle.

Retarded follicular and oocyte nucleolar growth rates in ovaries of 1 month old congenitally athymic nude mice are restored by pregnant mare serum gonadotrophin (PMSG). By contrast oestradiol-17beta depresses follicular growth rate in phenotypically normal (control) mice to levels found in nude littermates. Paradoxically, oestradiol-17beta stimulates nucleolar growth rate in control mice, but not nudes, to levels found in PMSG treated groups.

Ovarian development in athymic nude mice. III. The effect of PMSG and oestradiol upon the size and composition of the ovarian follicle population.

The response of 1 month old congenitally athymic nude mice and their phenotypically normal littermates to exogenous pregnant mare serum gonadotrophin (PMSG) and oestradiol-17beta has been tested. An equal increase in the number of growing follicles was detected in both nudes and controls in response to PMSG. A specific increase occurred in the number of unilaminar follicles in the initial growth stages in addition to the increase in the number of multilaminar and vesicular follicles.

Ovarian development in athymic nude mice. II. The growth of the oocyte and follicle.

Congenitally athymic mice homozygous for the Mendelian recessive mutation "nude" develop well defined morphological and quantitative changes in the ovarian follicle population. A decline in follicle numbers at 2 months of age is preceded by a retardation in follicle growth at 1 month of age. The growth of the oocyte and its nucleus are not affected by the nude mutation.

Ovarian development in athymic nude mice. The size and composition of the follicle population.

Mice homozygous for the Mendelian recessive mutation nude show a reduction in the size and changes in the composition of the ovarian follicle population. Follicular loss was first evident at 2 months of age and was specifically due to a reduction in the numbers of small (primordial) follicles and medium follicles in the initial growth stages. The first ovulation was delayed until 2 1/2 months of age.

Estimation of PFC and serum haemolysin response to SRBC in 'nude' mice.

The time course of the primary haemolysin response of thymusless `nude' mice to sheep red blood cells differs from that of intact animals in one main respect. After the initial peak, which is reached 4–6 days from injection of the cells, haemolysin level falls to zero at about Day 10; and there is a concurrent decline of the counts of plaque-forming cells. The prolonged phase of slow decline of haemolysin level, reflecting the production of 7S antibodies and typical of the response of normal animals, is absent.

Observations on the immunobiology of 'nude' mice.

Mice homozygous for the mutation , which are born without a thymus, accept allogeneic skin grafts. Prior intraperitoneal injection of a thymic cell suspension, or implantation of a thymus on the first day after birth, enables the `nude' mice to reject skin grafts. γ-Globulins are generally present in `nude' mice.

The lymphoid tissues in mice with congenital aplasia of the thymus.

The lymph nodes, spleens and Peyer's patches from seven mutant mice with agenesis of the thymus were compared with similar tissues from eight phenotypically normal littermate controls. In all lymph nodes examined from the mice the thymus-dependent areas were virtually `empty' of lymphocytes. In the corresponding areas in the spleen and Peyer's patches the numbers of lymphocytes were also significantly reduced.