Carbon for nutrient exchange between Lycopodiella inundata and Mucoromycotina fine root endophytes is unresponsive to high atmospheric CO2.

Non-vascular plants associating with arbuscular mycorrhizal (AMF) and Mucoromycotina ‘fine root endophyte’ (MFRE) fungi derive greater benefits from their fungal associates under higher atmospheric [CO2] (a[CO2]) than ambient; however, nothing is known about how changes in a[CO2] affect MFRE function in vascular plants. We measured movement of phosphorus (P), nitrogen (N) and carbon (C) between the lycophyte Lycopodiella inundata and Mucoromycotina fine root endophyte fungi using 33P-orthophosphate, 15 N-ammonium chloride and 14CO2 isotope tracers under ambient and elevated a[CO2] concentrations of 440 and 800 ppm, respectively. Transfers of 33P and 15 N from MFRE to plants were unaffected by changes in a[CO2]. There was a slight increase in C transfer from plants to MFRE under elevated a[CO2]. Our results demonstrate that the exchange of C-for-nutrients between a vascular plant and Mucoromycotina FRE is largely unaffected by changes in a[CO2]. Unravelling the role of MFRE in host plant nutrition and potential C-for-N trade changes between symbionts under different abiotic conditions is imperative to further our understanding of the past, present and future roles of plant-fungal symbioses in ecosystems

Heritable variation in maternally derived yolk androgens, thyroid hormones and immune factors

Maternal reproductive investment can critically influence offspring phenotype, and thus these maternal effects are expected to be under strong natural selection. Knowledge on the extent of heritable variation in the physiological mechanisms underlying maternal effects is however limited. In birds, resource allocation to eggs is a key mechanism for mothers to affect their offspring and different components of the egg may or may not be independently adjusted. We studied the heritability of egg components and their genetic and phenotypic covariation in great tits (Parus major), using captive-bred full siblings of wild origin. Egg mass, testosterone (T) and androstenedione (A4) hormone concentrations showed moderate heritability, in agreement with earlier findings. Interestingly, yolk triiodothyronine hormone (T3), but not its precursor, thyroxine hormone (T4), concentration was heritable. An immune factor, albumen lysozyme, showed moderate heritability, but yolk immunoglobulins (IgY) did not. The genetic correlation estimates were moderate but statistically nonsignificant; a trend for a positive genetic correlation was found between A4 and egg mass, T and lysozyme and IgY and lysozyme, respectively. Interestingly, phenotypic correlations were found only between A4 and T, and T4 and T3, respectively. Given that these egg components are associated with fitness-related traits in the offspring (and mother), and that we show that some components are heritable, it opens the possibility that natural selection may shape the rate and direction of phenotypic change via egg composition

Cervical myelopathy caused by soft-tissue mass in diffuse idiopathic skeletal hyperostosis

A rare case of cervical spinal cord compression in diffuse idiopathic skeletal hyperostosis (DISH or Forestier’s Disease) caused by a craniocervical mass of soft-tissue is reported. The objective is to describe an uncommon mechanism of spinal cord compression in DISH. Three weeks after a cardiac infarction a 69-year-old man slowly developed spastic tetraparesis. Magnetic resonance tomography showed a craniocervical tumor compressing the spinal cord and a massive DISH of the cervical spine. An extended mass of yellowish amorphous material was removed from between the dura, the posterior odontoid process and the posterior aspect of vertebral body C2 reaching to the upper part of C3.The histologic appearance indicated connective tissue and cell-degenerated cartilaginous tissue. There was no inflammatory component and no evidence of neoplasia. No ossification of the posterior longitudinal ligament (OPLL) was found. After removal and craniocervical stabilization the patient’s neurologic function improved remarkably. The increase of mechanical stress on the atlantoaxial segment and enhanced proliferation reaction of the connective tissue in DISH are suggested as the underlying pathomechanisms in the formation of this soft-tissue mass