Rescue specialists in Cataglyphis piliscapa ants: The nature and development of ant first responders.

Previous research in our laboratories has demonstrated that, within each colony of Cataglyphis piliscapa (formerly C. cursor) ants, only some individuals are capable of performing a complex sequence of behavioral patterns to free trapped nestmates-a sequence that not only is memory-dependent but also is responsive to the particular circumstances of that entrapment and how the rescue operation unfolds. Additionally, this rescue behavior is inherited patrilineally from but a few of the many males that fertilize the eggs of the colony's single queen. Here, we describe three experiments to explore rescue behavior further-namely, whether rescuers are in any way selective about which nestmates they help, how the age of rescuers and the victims that they help affect the quantity and quality of the rescue operation, and when this complex behavior first emerges in an ant's development. Taken together with the previous heritability analysis, these behavioral experiments provide clear evidence that the ability to rescue nestmates in distress should be recognized as a specialization, which together with other specialized tasks in C. piliscapa, contributes to a division of labor that increases the efficiency of the colony as a whole and, thus increases its reproductive success.

Prolonged care and cannibalism of infant corpse by relatives in semi-free-ranging capuchin monkeys.

Cannibalism is a quite common behaviour in animals that can have survival value when food is scarce or in the case of overpopulation. Conversely, cannibalism can also increase pathogen transmission and reduce fitness. In primates, some cases of cannibalism are associated with infanticide or are performed by mothers after their newborn has died (filial cannibalism). We report here the first observation of cannibalism, specifically infant cannibalism, in a semi-free-ranging group of brown capuchin monkeys (Sapajus apella). The baby was likely stillborn, as parts of the cranial bones were missing and no fresh injuries were visible. After half a day of taking care of the dead infant, the mother ate part of the corpse's skin and the highly nutritional viscera, possibly thereby compensating for the physiological costs of pregnancy. After attentively watching his mother's behaviour, the older brother of the dead newborn similarly ate parts of the corpse. Although we cannot rule out idiosyncrasy and vertical social transmission, it is possible that cannibalism is a normal-albeit rare-part of the behavioural repertoire of capuchin monkeys.

Characterization of antirrhinum petal development and identification of target genes of the class B MADS box gene DEFICIENS.

The class B MADS box transcription factors DEFICIENS (DEF) and GLOBOSA (GLO) of Antirrhinum majus together control the organogenesis of petals and stamens. Toward an understanding of how the downstream molecular mechanisms controlled by DEF contribute to petal organogenesis, we conducted expression profiling experiments using macroarrays comprising >11,600 annotated Antirrhinum unigenes. First, four late petal developmental stages were compared with sepals. More than 500 ESTs were identified that comprise a large number of stage-specifically regulated genes and reveal a highly dynamic transcriptional regulation. For identification of DEF target genes that might be directly controlled by DEF, we took advantage of the temperature-sensitive def-101 mutant. To enhance the sensitivity of the profiling experiments, one petal developmental stage was selected, characterized by increased transcriptome changes that reflect the onset of cell elongation processes replacing cell division processes. Upon reduction of the DEF function, 49 upregulated and 52 downregulated petal target genes were recovered. Eight target genes were further characterized in detail by RT-PCR and in situ studies. Expression of genes responding rapidly toward an altered DEF activity is confined to different petal tissues, demonstrating the complexity of the DEF function regulating diverse basic processes throughout petal morphogenesis.

Ancestry and diversity of BEL1-like homeobox genes revealed by gymnosperm ( Gnetum gnemon) homologs.

BEL1-like homeobox genes encode plant-specific transcription factors, at least some of which are important for ovule development. Here we report MELBEL1-MELBEL4,the first BEL1-like genes from a non-flowering plant, the gymnosperm Gnetum gnemon. Our analyses suggest that there was already at least one BEL1-like gene present in the most recent common ancestor of extant seed plants about 300 million years ago. Multiple sequence alignments revealed that since this time, not only the DNA-binding homeodomain, but also a protein-protein interaction domain upstream of the homeodomain, termed the BEL domain, has been highly conserved. Sequence comparison of the BEL domain with upstream domains that have been conserved in other TALE homeodomain proteins, i.e. MEIS, KNOX, and PBC, revealed only weak sequence similarity. However, since homology has been shown for MEIS, KNOX, and PBC domains and since KNOX and BEL domains directly interact in vivo, it appears likely that the BEL domain was also derived from an ancestral upstream (MEINOX) domain.