ECM-mediated positional cues are able to induce pattern, but not new positional information, during axolotl limb regeneration.

The Mexican Axolotl is able to regenerate missing limb structures in any position along the limb axis throughout its life and serves as an excellent model to understand the basic mechanisms of endogenous regeneration. How the new pattern of the regenerating axolotl limb is established has not been completely resolved. An accumulating body of evidence indicates that pattern formation occurs in a hierarchical fashion, which consists of two different types of positional communications. The first type (Type 1) of communication occurs between connective tissue cells, which retain memory of their original pattern information and use this memory to generate the pattern of the regenerate. The second type (Type 2) of communication occurs from connective tissue cells to other cell types in the regenerate, which don't retain positional memory themselves and arrange themselves according to these positional cues. Previous studies suggest that molecules within the extracellular matrix (ECM) participate in pattern formation in developing and regenerating limbs. However, it is unclear whether these molecules play a role in Type 1 or Type 2 positional communications. Utilizing the Accessory Limb Model, a regenerative assay, and transcriptomic analyses in regenerates that have been reprogrammed by treatment with Retinoic Acid, our data indicates that the ECM likely facilities Type-2 positional communications during limb regeneration.

Infertility Centrality in the Woman's Identity and Goal Adjustment Predict Psychological Adjustment Among Women in Ongoing Fertility Treatments.

PURPOSE: Some of the women that go through repeated fertility treatments will not adjust well to the treatments and will experience increased distress. The present study examined how centrality of the fertility problem in the woman's identity and dispositional goal adjustment (disengagement and reengagement) are associated with the woman's psychological adjustment. These issues are examined in a context of a pro-natal society (Israel) where parenthood is a major life goal. METHODS: One hundred ninety-three women in ongoing fertility treatments filled out questionnaires, and follow-up on their psychological well-being was carried out after 3 months (N = 130). RESULTS: Women who perceived their fertility problem as more central to their identity experienced greater distress (ß = 0.34, p < 0.01) and less well-being (ß = - 0.31, p < 0.01). Concurrently, high ability for goal disengagement was a resource that protected women from these feelings. Women high on goal disengagement who were low on goal reengagement experienced greater distress (ß of interaction = - 0.24, p < 0.01), probably because they remained with feelings of emptiness and lack of purpose. These findings were found in both cross-sectional and longitudinal analyses. Finally, the models predicting well-being and distress at T2 using centrality, goal adjustment, and T1 well-being/distress explained 42 and 47.5% of the variance, respectively. CONCLUSIONS: Much research and therapeutic attention has been invested in coping with fertility treatments, while the options of reducing investment in treatments and finding alternative goals did not receive adequate attention. This study discusses these issues and their possible clinical implications especially in a pro-natal context.