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ABSTRACT Functional studies of host-microbe interactions benefit from natural model systems that enable the exploration of molecular mechanisms at the host-microbe interface. BioluminescentVibrio fischericolonize the light organ of the Hawaiian bobtail squid,Euprymna scolopes, and this binary model has enabled advances in understanding host-microbe communication, colonization specificity,in vivobiofilms, intraspecific competition, and quorum sensing. The hummingbird bobtail squid,Euprymna berryi,can be generationally bred and maintained in lab settings and has had multiple genes deleted by CRISPR approaches. The prospect of expanding the utility of the light organ model system by producing multigenerational host lines led us to determine the extent to which theE. berryilight organ symbiosis parallels known processes inE. scolopes. However, the nature of theE. berryilight organ, including its microbial constituency and specificity for microbial partners, has not been examined. In this report, we isolated bacteria fromE. berryianimals and tank water. Assays of bacterial behaviors required in the host, as well as host responses to bacterial colonization, illustrate largely parallel phenotypes inE. berryiandE. scolopeshatchlings. This study revealsE. berryito be a valuable comparative model to complement studies inE. scolopes.IMPORTANCEMicrobiome studies have been substantially advanced by model systems that enable functional interrogation of the roles of the partners and the molecular communication between those partners. TheEuprymna scolopes-Vibrio fischerisystem has contributed foundational knowledge, revealing key roles for bacterial quorum sensing broadly and in animal hosts, for bacteria in stimulating animal development, for bacterial motility in accessing host sites, and forin vivobiofilm formation in development and specificity of an animal’s microbiome.Euprymna berryiis a second bobtail squid host, and one that has recently been shown to be robust to laboratory husbandry and amenable to gene knockout. This study identifiesE. berryias a strong symbiosis model host due to features that are conserved with those ofE. scolopes, which will enable the extension of functional studies in bobtail squid symbioses. 

Depletion attractions drive bacterial adhesion on non-adhesive surfaces, enhance cell capture on adhesive surfaces, immobilize bacterial cells flat to a surface, and help align cells gentle flow. 

We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries Bn on 12C and 27Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of Bn on 12C and provide a first measurement on 27Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average laboratory scattering angle for both targets was 7.7∘, and the average Q2 for both targets was 0.024 37 GeV2 (Q=0.1561 GeV). The asymmetries are Bn=−10.68±0.90(stat)±0.57(syst) ppm for 12C and Bn=−12.16±0.58(stat)±0.62(syst) ppm for 27Al. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by Z/A, the Q dependence of all the far-forward angle (θ<10∘) data from 1H to 27Al can be described by the same slope out to Q≈0.35 GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep. 

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θlab=7.9° and a mean energy of 1.149 GeV. The asymmetry result is Bn=−5.194±0.067(stat)±0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (θlab→0) where they should be most reliable.