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Fish pituitary plays a central role in the control of growth, development, reproduction and adaptation to the environment. Several types of hormone-secreting adenohypophyseal cells have been characterised and localised in diverse teleost species. The results suggest a similar distribution pattern among the species investigated. However, most studies deal with a single hormone or hormone family. Thus, we studied adjacent sections of the pituitary of Oreochromis niloticus, the tilapia, by conventional staining and immunohistochemistry with specific antisera directed against growth hormone (GH), prolactin (PRL), somatolactin (SL), thyrotropin (β-TSH), follicle-stimulating hormone (β-FSH), luteinising hormone (β-LH), adrenocorticotropic hormone (ACTH) and melanocyte-stimulating hormone (α-MSH). The pituitary was characterised by a close interdigitating neighbourhood of neurohypophysis (PN) and adenohypophysis. PRL-immunoreactive and ACTH-immunoreactive cells were detected in the rostral pars distalis. GH-immunoreactive cells were present in the proximal pars distalis (PPD). A small region of the PPD contained β-TSH-immunoreactive cells, and β-LH-immunoreactive cells covered approximately the remaining parts. Centrally, β-FSH-immunoreactive cells were detected in the vicinity of the GH-containing cells. Some of these cells also displayed β-LH immunoreactivity. The pars intermedia was characterised by branches of the PN surrounded by SL-containing and α-MSH-immunoreactive cells.The ACTH and α-MSH antisera were observed to cross-react with the respective antigens. This cross-reactivity was abolished by pre-absorption. We present a complete map of the distinct localisation sites for the classical pituitary hormones, thereby providing a solid basis for future research on teleost pituitary

IGF-I plays a crucial role in the regulation of bony fish growth, differentiation, and reproduction. The major source of circulating IGF-I is liver, but IGF-I-producing cells also occur in other organs. Our knowledge on the presence of IGF-I in the hypothalamic-pituitary-gonadal (HPG) axis is limited. Thus, hypothalamus, pituitary and gonads of monosex breedings of male and female tilapia from 0 day post fertilization (DPF) to adulthood were investigated for the occurrence of IGF-I mRNA by in situ hybridization. In the male and female gonad anlage, IGF-I mRNA appeared in somatic cells at 7 DPF. In female germ cells IGF-I mRNA was found at 29 DPF, and in male germ cells at 51-53 DPF suggesting that the production of IGF-I in the germ cells is linked to the onset of meiosis. In the neurohypophysis, axons containing IGF-I-immunoreactivity appeared around 17 DPF but no IGF-I mRNA was detected suggesting that IGF-I mRNA containing neuronal perikarya within the hypothalamus are the source. In the adenopituitary, IGF-I mRNA was first detected at 30 DPF in some cells of the ACTH, α-MSH and GH regions and persisted throughout life constitutively in ACTH and α-MSH cells but its presence in GH cells showed marked inter-individual differences in later life, the latter likely due to the physiological status of the individual. Around 30 DPF, IGF-I mRNA appeared in cells in the gonadotropin (GTH) regions of the female and at 50 DPF of the male pituitary. During puberty (around 80 DPF), the expression of IGF-I mRNA in GTH cells was most pronounced in both sexes. It is assumed that IGF-I released from the GTH cells acts as auto/paracrine regulator of cell proliferation and enhances GTH synthesis and release during puberty and reproductive phases.

Mummified human tissues are of great interest in forensics and biomolecular archaeology. The aim of this study was to analyse post mortem DNA alterations in soft tissues in order to improve our knowledge of the patterns of DNA degradation that occur during salt mummification. In this study, the lower limb of a female human donor was amputated within 24 h post mortem and mummified using a process designed to simulate the salt dehydration phase of natural or artificial mummification. Skin and skeletal muscle were sampled at multiple time points over a period of 322 days and subjected to genetic analysis. Patterns of genomic fragmentation, miscoding lesions, and overall DNA degradation in both nuclear and mitochondrial DNA was assessed by different methods: gel electrophoresis, multiplex comparative autosomal STR length amplification, cloning and sequence analysis, and PCR amplification of different fragment sizes using a damage sensitive recombinant polymerase. The study outcome reveals a very good level of DNA preservation in salt mummified tissues over the course of the experiment, with an overall slower rate of DNA fragmentation in skin compared to muscle.