The Wnt Target Protein Peter Pan Defines a Novel p53-independent Nucleolar Stress-Response Pathway

Proper ribosome formation is a prerequisite for cell growth and proliferation. Failure of this process results in nucleolar stress and p53-mediated apoptosis. The Wnt target Peter Pan (PPAN) is required for 45 S rRNA maturation. So far, the role of PPAN in nucleolar stress response has remained elusive. We demonstrate that PPAN localizes to mitochondria in addition to its nucleolar localization and inhibits the mitochondrial apoptosis pathway in a p53-independent manner. Loss of PPAN induces BAX stabilization, depolarization of mitochondria, and release of cytochrome c, demonstrating its important role as an anti-apoptotic factor. Staurosporine-induced nucleolar stress and apoptosis disrupt nucleolar PPAN localization and induce its accumulation in the cytoplasm. This is accompanied by phosphorylation and subsequent cleavage of PPAN by caspases. Moreover, we show that PPAN is a novel interaction partner of the anti-apoptotic protein nucleophosmin (NPM). PPAN depletion induces NPM and upstream-binding factor (UBF) degradation, which is independent of caspases. In summary, we provide evidence for a novel nucleolar stress-response pathway involving PPAN, NPM, and BAX to guarantee cell survival in a p53-independent manner.     

Birth of a chimpanzee (Pan troglodytes) after artificial insemination with cryopreserved epididymal spermatozoa collected postmortem

A male chimpanzee (Pan troglodytes) suddenly died of acute hemorrhagic enteritis at the age of 18 years. Within 24 hours after its death, a large quantity of spermatozoa of excellent quality was recovered from the distal cauda epididymides and was subsequently cryopreserved. After storage for 67 days, the frozen spermatozoa were thawed and inseminated in an adult, normal cycling, nulliparous female. The optimal day for insemination was estimated by monitoring the swelling of the female’s sex skin and urinary luteinizing hormone concentrations. Pregnancy was confirmed by a urinary chorionic gonadotropin test, and a normal female infant was born after 214 days of gestation. This birth demonstrates that distal cauda epididymal spermatozoa recovered from a dead male can be cryopreserved and successfully inseminated in a female chimpanzee. Zoo Biol 20:135–143, 2001. © 2001 Wiley‐Liss, Inc.     

The home range of the Sonso community of chimpanzees from the Budongo Forest, Uganda

Early studies of chimpanzees in the Budongo Forest, Uganda, reported only rough estimates for home range size. This study aimed to quantify home range size and habitat composition for chimpanzees of the Sonso community in this forest. Home range is the habitually used portion of the total area over which an animal travels, and for chimpanzees the home range is shared by the community. From data collected in 1994 and 1995, the home range for this community was estimated to cover an area of 6.78 km² using the minimum convex polygon analysis technique and 6.89 km² using fixed kernel analysis. Habitat was highly heterogeneous. The small home range and consequent high local population density (approximately 6.8 individuals km^?1) suggests that the Sonso region is highly productive in chimpanzee foods, possibly in contrast to other parts of the forest. This estimate of home range size is among the smallest reported for habituated chimpanzees, but comparisons with other sites are confounded by methodological and analytical differences. Future studies of chimpanzee ranging patterns should endeavour to use precise locations and the latest analytical techniques to ensure accurate estimation of range size and structure, and intersite comparability.     

Structural basis for Pan3 binding to Pan2 and its function in mRNA recruitment and deadenylation

The conserved eukaryotic Pan2–Pan3 deadenylation complex shortens cytoplasmic mRNA 3′ polyA tails to regulate mRNA stability. Although the exonuclease activity resides in Pan2, efficient deadenylation requires Pan3. The mechanistic role of Pan3 is unclear. Here, we show that Pan3 binds RNA directly both through its pseudokinase/C‐terminal domain and via an N‐terminal zinc finger that binds polyA RNA specifically. In contrast, isolated Pan2 is unable to bind RNA. Pan3 binds to the region of Pan2 that links its N‐terminal WD40 domain to the C‐terminal part that contains the exonuclease, with a 2:1 stoichiometry. The crystal structure of the Pan2 linker region bound to a Pan3 homodimer shows how the unusual structural asymmetry of the Pan3 dimer is used to form an extensive high‐affinity interaction. This binding allows Pan3 to supply Pan2 with substrate polyA RNA, facilitating efficient mRNA deadenylation by the intact Pan2–Pan3 complex.     

Logical Structures of Young Chimpanzees' Spontaneous Object Grouping

I investigated sensorimotor precursors of logicoarithmetic operations involved in spontaneous object grouping of five common chimpanzees aged 1 to 4 years. I considered three basic logical relations between objects or sets of objects: equivalence, order, and reversibility relations. Chimpanzees introduced equivalence and order relations within sets of objects as well as between sets. They showed a higher level of logical organization than monkeys do. Compared to human infants, chimpanzees manifested a specific difference and a specific delay. First, chimpanzees only partially mapped the logical properties of their action organization on sets of objects. For example, chimpanzees' simultaneous acts on two sets of objects, though increasing with age, almost never resulted in spatial correspondences between the sets. Secondly, they showed a specific delay in that they produced scarcely any form of reversibility.     

Straw and forage material ameliorate abnormal behaviors in adult chimpanzees

In an effort reduce abnormal behaviors, especially regurgitation and reingestion, and promote higher activate levels, straw and scattered forage material were added to the enclosures of 13 indoor-housed chimpanzees (Pan troglodytes) living in pairs and trios. Behavioral effects were examined by comparing 65 hr in the baseline condition with 65 hr in the experimental condition. Subjects spent 8.7% of observed time foraging or otherwise manipulating the straw, and no evidence of habituation was found over 9 weeks. Males foraged at a rate three times that of females. Overall, abnormal behavior was significantly reduced. Examined alone, regurgitation and reingestion levels fell to less than one-third their former level and ceased to rise with elapsed time since feeding. Subjects spent less time displaying and more time locomoting and playing. This enrichment option was found to be practical in terms of caretaker effort and expense and caused no health problems. Zoo Biol 16:225–236, 1997. © 1997 Wiley-Liss, Inc.     

Long-term results of evaporation rate in xerothermic Oak altitudinal vegetation stage in Southern Slovakia

The paper presents the results of the model computation of actual and potential evapotranspiration as well as evaporation measurements from the GGI-3000 Pan (evaporimeter) at 3 selected stations of Slovakia for the periods 1971–2000 (2 stations) and 1986–2000 (1 station). The localities are situated in the most southern parts of Slovakia in 1^st Oak stage and on southern slopes of the Carpathian promontories. A model computation of the monthly totals of actual and potential evapotranspiration was performed by a common solution of energy and water balance equations of the top one-meter layer of the soil. The model outputs are compared to the measurement data. The dependence of the ratio of actual evapotranspiration/ evaporation measured by the GGI-3000 Pan (E/E _p) on relative evapotranspiration (E/E _o), when E, E _o are calculated, is linear with a high correlation coefficient during the season from April to October. The paper also gives the comparison results of the mean monthly and annual air temperatures, temperatures of active and saturated surface with the mean monthly temperature of free water surface in the GGI-3000 Pan at these 3 stations (Bratislava-Koliba, Somotor and Žihárec). It was found that the mean free water surface temperature for the period from April to October is close to the mean temperature of saturated surface during that period. The mean temperatures of free water surface in the GGI-3000 Pan from April to October tend to increase for the period 1971–2000.